morph dataloader specific (#13259)

In the metadata GraphQL api, we need the resolveField for the
morphRelations. This PR implements this topic.


Fixes https://github.com/twentyhq/core-team-issues/issues/1234

---------

Co-authored-by: Charles Bochet <charles@twenty.com>

packages/twenty-server/src/engine/utils/is-morph-relation-field-metadata-type.util.ts

@@ -0,0 +1,7 @@
+import { FieldMetadataType } from 'twenty-shared/types';
+
+export const isMorphRelationFieldMetadataType = (
+  type: FieldMetadataType,
+): type is FieldMetadataType.MORPH_RELATION => {
+  return type === FieldMetadataType.MORPH_RELATION;
+};