Change DatastoreAccess::Tree typedef

Before this, the order of items we get in DatastoreAccess::getItems
wasn't preserved. Because (leaf)lists can be ordered, we need to
preserver the order.

Change-Id: Ie4914025b7d868fd9cbbea5e4f1498115030d126
diff --git a/tests/datastore_access.cpp b/tests/datastore_access.cpp
index e11eec5..07320c9 100644
--- a/tests/datastore_access.cpp
+++ b/tests/datastore_access.cpp
@@ -202,7 +202,7 @@
             datastore.commitChanges();
         }
 
-        DatastoreAccess::Tree expected{{"/example-schema:down", bool{false}},
+        DatastoreAccess::Tree expected{
         // Sysrepo always returns containers when getting values, but
         // libnetconf does not. This is fine by the YANG standard:
         // https://tools.ietf.org/html/rfc7950#section-7.5.7 Furthermore,
@@ -212,10 +212,11 @@
         // because it'll use the same data structure as libnetconf, so the
         // results will be consistent.
 #ifdef sysrepo_BACKEND
-                                                   {"/example-schema:lol", special_{SpecialValue::Container}},
                                                    {"/example-schema:inventory", special_{SpecialValue::Container}},
+                                                   {"/example-schema:lol", special_{SpecialValue::Container}},
 #endif
-                                                   {"/example-schema:up", bool{true}}};
+                                                   {"/example-schema:up", bool{true}},
+                                                   {"/example-schema:down", bool{false}}};
         REQUIRE(datastore.getItems("/example-schema:*") == expected);
     }