Unify item creation/deletion in datastore access

All of our implementations are using the same implementation; all of the
smartness is actually in sysrepo or in libyang. As a bonus, this should
make it possible to remove regular leafs as well (backend-wise at
least).

Change-Id: I177cd233b4b699f66475eae735a659b7c8577534
diff --git a/tests/datastore_access.cpp b/tests/datastore_access.cpp
index e9030db..bab7fac 100644
--- a/tests/datastore_access.cpp
+++ b/tests/datastore_access.cpp
@@ -133,7 +133,7 @@
     SECTION("create presence container")
     {
         REQUIRE_CALL(mock, write("/example-schema:pContainer", std::nullopt, ""s));
-        datastore.createPresenceContainer("/example-schema:pContainer");
+        datastore.createItem("/example-schema:pContainer");
         datastore.commitChanges();
     }
 
@@ -142,13 +142,13 @@
         {
             REQUIRE_CALL(mock, write("/example-schema:person[name='Nguyen']", std::nullopt, ""s));
             REQUIRE_CALL(mock, write("/example-schema:person[name='Nguyen']/name", std::nullopt, "Nguyen"s));
-            datastore.createListInstance("/example-schema:person[name='Nguyen']");
+            datastore.createItem("/example-schema:person[name='Nguyen']");
             datastore.commitChanges();
         }
         {
             REQUIRE_CALL(mock, write("/example-schema:person[name='Nguyen']", ""s, std::nullopt));
             REQUIRE_CALL(mock, write("/example-schema:person[name='Nguyen']/name", "Nguyen"s, std::nullopt));
-            datastore.deleteListInstance("/example-schema:person[name='Nguyen']");
+            datastore.deleteItem("/example-schema:person[name='Nguyen']");
             datastore.commitChanges();
         }
     }
@@ -156,15 +156,15 @@
     SECTION("deleting non-existing list keys")
     {
         tryThis<THROWS_ON_NONEXISTING_KEYS>([&]{
-            datastore.deleteListInstance("/example-schema:person[name='non existing']");
+            datastore.deleteItem("/example-schema:person[name='non existing']");
             datastore.commitChanges();
         });
     }
 
-    SECTION("accessing non-existing schema nodes")
+    SECTION("deleting non-existing schema nodes as a list")
     {
         tryThis<THROWS_ON_INVALID_SCHEMA_PATHS>([&]{
-            datastore.deleteListInstance("/example-schema:non-existing-list[xxx='non existing']");
+            datastore.deleteItem("/example-schema:non-existing-list[xxx='non existing']");
             datastore.commitChanges();
         });
     }
@@ -178,9 +178,9 @@
             REQUIRE_CALL(mock, write("/example-schema:person[name='Elfi']/name", std::nullopt, "Elfi"s));
             REQUIRE_CALL(mock, write("/example-schema:person[name='Kolafa']", std::nullopt, ""s));
             REQUIRE_CALL(mock, write("/example-schema:person[name='Kolafa']/name", std::nullopt, "Kolafa"s));
-            datastore.createListInstance("/example-schema:person[name='Dan']");
-            datastore.createListInstance("/example-schema:person[name='Elfi']");
-            datastore.createListInstance("/example-schema:person[name='Kolafa']");
+            datastore.createItem("/example-schema:person[name='Dan']");
+            datastore.createItem("/example-schema:person[name='Elfi']");
+            datastore.createItem("/example-schema:person[name='Kolafa']");
             datastore.commitChanges();
         }
 
@@ -269,9 +269,9 @@
             REQUIRE_CALL(mock, write("/example-schema:person[name='Michal']/name", std::nullopt, "Michal"s));
             REQUIRE_CALL(mock, write("/example-schema:person[name='Petr']", std::nullopt, ""s));
             REQUIRE_CALL(mock, write("/example-schema:person[name='Petr']/name", std::nullopt, "Petr"s));
-            datastore.createListInstance("/example-schema:person[name='Jan']");
-            datastore.createListInstance("/example-schema:person[name='Michal']");
-            datastore.createListInstance("/example-schema:person[name='Petr']");
+            datastore.createItem("/example-schema:person[name='Jan']");
+            datastore.createItem("/example-schema:person[name='Michal']");
+            datastore.createItem("/example-schema:person[name='Petr']");
             datastore.commitChanges();
         }
         DatastoreAccess::Tree expected{
@@ -294,7 +294,7 @@
 
         {
             REQUIRE_CALL(mock, write("/example-schema:pContainer", std::nullopt, ""s));
-            datastore.createPresenceContainer("/example-schema:pContainer");
+            datastore.createItem("/example-schema:pContainer");
             datastore.commitChanges();
         }
         expected = {
@@ -305,17 +305,17 @@
         // Make sure it's not there after we delete it
         {
             REQUIRE_CALL(mock, write("/example-schema:pContainer", ""s, std::nullopt));
-            datastore.deletePresenceContainer("/example-schema:pContainer");
+            datastore.deleteItem("/example-schema:pContainer");
             datastore.commitChanges();
         }
         expected = {};
         REQUIRE(datastore.getItems("/example-schema:pContainer") == expected);
     }
 
-    SECTION("non-existing persistent container schema node")
+    SECTION("deleting a non-existing schema node as a container or leaf")
     {
         tryThis<THROWS_ON_INVALID_SCHEMA_PATHS>([&]{
-            datastore.deletePresenceContainer("/example-schema:non-existing-presence-container");
+            datastore.deleteItem("/example-schema:non-existing-presence-container");
             datastore.commitChanges();
         });
     }
@@ -328,7 +328,7 @@
         {
             REQUIRE_CALL(mock, write("/example-schema:inventory", std::nullopt, ""s));
             REQUIRE_CALL(mock, write("/example-schema:inventory/stuff", std::nullopt, ""s));
-            datastore.createPresenceContainer("/example-schema:inventory/stuff");
+            datastore.createItem("/example-schema:inventory/stuff");
             datastore.commitChanges();
         }
         expected = {
@@ -338,7 +338,7 @@
         {
             REQUIRE_CALL(mock, write("/example-schema:inventory", ""s, std::nullopt));
             REQUIRE_CALL(mock, write("/example-schema:inventory/stuff", ""s, std::nullopt));
-            datastore.deletePresenceContainer("/example-schema:inventory/stuff");
+            datastore.deleteItem("/example-schema:inventory/stuff");
             datastore.commitChanges();
         }
         expected = {};
@@ -428,8 +428,8 @@
         DatastoreAccess::Tree expected;
         REQUIRE_CALL(mock, write("/example-schema:addresses", std::nullopt, "0.0.0.0"s));
         REQUIRE_CALL(mock, write("/example-schema:addresses", std::nullopt, "127.0.0.1"s));
-        datastore.createLeafListInstance("/example-schema:addresses[.='0.0.0.0']");
-        datastore.createLeafListInstance("/example-schema:addresses[.='127.0.0.1']");
+        datastore.createItem("/example-schema:addresses[.='0.0.0.0']");
+        datastore.createItem("/example-schema:addresses[.='127.0.0.1']");
         datastore.commitChanges();
         expected = {
             {"/example-schema:addresses", special_{SpecialValue::LeafList}},
@@ -439,7 +439,7 @@
         REQUIRE(datastore.getItems("/example-schema:addresses") == expected);
 
         REQUIRE_CALL(mock, write("/example-schema:addresses", "0.0.0.0"s, std::nullopt));
-        datastore.deleteLeafListInstance("/example-schema:addresses[.='0.0.0.0']");
+        datastore.deleteItem("/example-schema:addresses[.='0.0.0.0']");
         datastore.commitChanges();
         expected = {
             {"/example-schema:addresses", special_{SpecialValue::LeafList}},
@@ -448,24 +448,24 @@
         REQUIRE(datastore.getItems("/example-schema:addresses") == expected);
 
         REQUIRE_CALL(mock, write("/example-schema:addresses", "127.0.0.1"s, std::nullopt));
-        datastore.deleteLeafListInstance("/example-schema:addresses[.='127.0.0.1']");
+        datastore.deleteItem("/example-schema:addresses[.='127.0.0.1']");
         datastore.commitChanges();
         expected = {};
         REQUIRE(datastore.getItems("/example-schema:addresses") == expected);
     }
 
-    SECTION("non-existing leaf-list")
+    SECTION("deleting a non-existing leaf-list")
     {
         tryThis<THROWS_ON_NONEXISTING_KEYS>([&]{
-            datastore.deleteLeafListInstance("/example-schema:addresses[.='non-existing']");
+            datastore.deleteItem("/example-schema:addresses[.='non-existing']");
             datastore.commitChanges();
         });
     }
 
-    SECTION("non-existing leaf-list schema node")
+    SECTION("deleting a non-existing schema node as a leaf-list")
     {
         tryThis<THROWS_ON_INVALID_SCHEMA_PATHS>([&]{
-            datastore.deleteLeafListInstance("/example-schema:non-existing[.='non-existing']");
+            datastore.deleteItem("/example-schema:non-existing[.='non-existing']");
             datastore.commitChanges();
         });
     }
@@ -494,9 +494,9 @@
             REQUIRE_CALL(mock, write("/example-schema:protocols", std::nullopt, "pop3"s));
             REQUIRE_CALL(mock, write("/example-schema:protocols", "http"s, "ftp"s));
             REQUIRE_CALL(mock, write("/example-schema:protocols", "ftp"s, "pop3"s));
-            datastore.createLeafListInstance("/example-schema:protocols[.='http']");
-            datastore.createLeafListInstance("/example-schema:protocols[.='ftp']");
-            datastore.createLeafListInstance("/example-schema:protocols[.='pop3']");
+            datastore.createItem("/example-schema:protocols[.='http']");
+            datastore.createItem("/example-schema:protocols[.='ftp']");
+            datastore.createItem("/example-schema:protocols[.='pop3']");
             datastore.commitChanges();
             expected = {
                 {"/example-schema:protocols", special_{SpecialValue::LeafList}},
@@ -582,9 +582,9 @@
             REQUIRE_CALL(mock, write("/example-schema:players[name='Adam']", std::nullopt, ""s));
             REQUIRE_CALL(mock, write("/example-schema:players[name='Adam']/name", std::nullopt, "Adam"s));
             REQUIRE_CALL(mock, write("/example-schema:players[name='Adam']", ""s, ""s));
-            datastore.createListInstance("/example-schema:players[name='John']");
-            datastore.createListInstance("/example-schema:players[name='Eve']");
-            datastore.createListInstance("/example-schema:players[name='Adam']");
+            datastore.createItem("/example-schema:players[name='John']");
+            datastore.createItem("/example-schema:players[name='Eve']");
+            datastore.createItem("/example-schema:players[name='Adam']");
             datastore.commitChanges();
             expected = {
                 {"/example-schema:players[name='John']", special_{SpecialValue::List}},