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/src/datastore_access.hpp b/src/datastore_access.hpp
index 05c1296..0856d41 100644
--- a/src/datastore_access.hpp
+++ b/src/datastore_access.hpp
@@ -46,12 +46,8 @@
     virtual ~DatastoreAccess() = 0;
     virtual Tree getItems(const std::string& path) = 0;
     virtual void setLeaf(const std::string& path, leaf_data_ value) = 0;
-    virtual void createPresenceContainer(const std::string& path) = 0;
-    virtual void deletePresenceContainer(const std::string& path) = 0;
-    virtual void createListInstance(const std::string& path) = 0;
-    virtual void deleteListInstance(const std::string& path) = 0;
-    virtual void createLeafListInstance(const std::string& path) = 0;
-    virtual void deleteLeafListInstance(const std::string& path) = 0;
+    virtual void createItem(const std::string& path) = 0;
+    virtual void deleteItem(const std::string& path) = 0;
     virtual void moveItem(const std::string& path, std::variant<yang::move::Absolute, yang::move::Relative> move) = 0;
     virtual Tree executeRpc(const std::string& path, const Tree& input) = 0;