Add applicationId to syncableEntity and fix syncApp deletion (#15170)

## Context
- All flatEntity should extend SyncableEntity
- SyncableEntity should now have applicationId and application relation
- Fix syncApp deletion, should now properly use migration v2 to delete
syncable entities

packages/twenty-server/src/engine/metadata-modules/flat-view-group/utils/from-create-view-group-input-to-flat-view-group-to-create.util.ts

@@ -28,9 +28,11 @@ export const fromCreateViewGroupInputToFlatViewGroupToCreate = ({
     createdAt: createdAt,
     updatedAt: createdAt,
     deletedAt: null,
-    universalIdentifier: viewGroupId,
+    universalIdentifier:
+      createViewGroupInput.universalIdentifier ?? viewGroupId,
     isVisible: createViewGroupInput.isVisible ?? true,
     fieldValue: createViewGroupInput.fieldValue,
     position: createViewGroupInput.position ?? 0,
+    applicationId: createViewGroupInput.applicationId ?? null,
   };
 };