Issue #AR-1_serialization: add tests comparing models generated object serializer and archetype.SerializeForPersistence() pathwways.

Note: SerializeForPersistence() does not generate escaped json when used on its own.
All tests passing.
Issue #AR-1_serialization: add test to try to create escaped json - this still produces unescaped json.

However,
		    internal virtual PropertyEditor GetPropertyEditor(IDataTypeDefinition dtd)
		    {
		        return dtd.Id == 0
                    ? new ArchetypePropertyEditor()
                    : PropertyEditorResolver.Current.GetByAlias(dtd.PropertyEditorAlias);
		    }

would produce nested json. But this spec looks incorrect.