feat: add Relation field form (#2572)

* feat: add useCreateOneRelationMetadata and useRelationMetadata

Closes #2423

* feat: add Relation field form

Closes #2003

---------

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

front/src/modules/settings/data-model/hooks/useRelationFieldPreview.ts

@@ -0,0 +1,29 @@
+import { useObjectMetadataItemForSettings } from '@/object-metadata/hooks/useObjectMetadataItemForSettings';
+import { useFindManyObjectRecords } from '@/object-record/hooks/useFindManyObjectRecords';
+
+export const useRelationFieldPreview = ({
+  relationObjectMetadataId,
+  skipDefaultValue,
+}: {
+  relationObjectMetadataId?: string;
+  skipDefaultValue: boolean;
+}) => {
+  const { findObjectMetadataItemById } = useObjectMetadataItemForSettings();
+
+  const relationObjectMetadataItem = relationObjectMetadataId
+    ? findObjectMetadataItemById(relationObjectMetadataId)
+    : undefined;
+
+  const { objects: relationObjects } = useFindManyObjectRecords({
+    objectNamePlural: relationObjectMetadataItem?.namePlural,
+    skip: skipDefaultValue || !relationObjectMetadataItem,
+  });
+
+  return {
+    defaultValue: relationObjects?.[0],
+    entityChipDisplayMapper: (fieldValue?: { id: string }) => ({
+      name: fieldValue?.id || relationObjectMetadataItem?.labelSingular || '',
+      avatarType: 'squared' as const,
+    }),
+  };
+};