copy method
Implementation
@override
Future<MonaStyle?> copy(AppModel app, String newName) async {
var newModel = monaStyleAttributesModel.copyWith(documentID: newName);
await monaStyleAttributesRepository(appId: app.documentID)!.add(newModel);
return MonaStyle(
styleFamily, newName, AllowedUpdates.allAllowed(), newModel);
}