V14/fix/element switch validation (#16421)

* Added Element <-> Document type switch validation

* Apply HasElementconfigured to block grid and block list

Fix smalle bug + optimization

* Moved some of the logic into warnings trough notifcationhandlers and eventmessages

* Cleanup

* Update openApi spec (merge changes)

* Add IsElement check between parent and child on creation

* Typos

* Transformed HasElementConfigured into HasElementConfigured

* Typo

Co-authored-by: Kenn Jacobsen <kja@umbraco.dk>

* IsElement Validation refactor

Moved validation logic regarding doctype IsElement switch into its own service as it will be consumed by more things down the line

* commit missing services...

* Naming improvements

* Bugfix

* First batch of integration tests for ElementSwitchValidator

* More integration tests!

* Little reformatting

* Changed the default values of block based configuration to match expected values.

---------

Co-authored-by: Kenn Jacobsen <kja@umbraco.dk>

src/Umbraco.Infrastructure/PropertyEditors/BlockValuePropertyValueEditorBase.cs

@@ -114,6 +114,15 @@ public abstract class BlockValuePropertyValueEditorBase<TValue, TLayout> : DataV
         MapBlockItemDataToEditor(property, blockValue.SettingsData);
     }
 
+    protected IEnumerable<Guid> ConfiguredElementTypeKeys(IBlockConfiguration configuration)
+    {
+        yield return configuration.ContentElementTypeKey;
+        if (configuration.SettingsElementTypeKey is not null)
+        {
+            yield return configuration.SettingsElementTypeKey.Value;
+        }
+    }
+
     private void MapBlockItemDataToEditor(IProperty property, List<BlockItemData> items)
     {
         var valEditors = new Dictionary<Guid, IDataValueEditor>();