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/types/flat-view-group.type.ts

@@ -1,5 +1,6 @@
 import { type Workspace } from 'src/engine/core-modules/workspace/workspace.entity';
 import { type FieldMetadataEntity } from 'src/engine/metadata-modules/field-metadata/field-metadata.entity';
+import { type FlatEntityFrom } from 'src/engine/metadata-modules/flat-entity/types/flat-entity.type';
 import { type ViewGroupEntity } from 'src/engine/metadata-modules/view-group/entities/view-group.entity';
 import { type ViewEntity } from 'src/engine/metadata-modules/view/entities/view.entity';
 import { type ExtractRecordTypeOrmRelationProperties } from 'src/engine/workspace-manager/workspace-migration-v2/types/extract-record-typeorm-relation-properties.type';
@@ -10,9 +11,7 @@ export type ViewGroupEntityRelationProperties =
     FieldMetadataEntity | ViewEntity | Workspace
   >;
 
-export type FlatViewGroup = Omit<
+export type FlatViewGroup = FlatEntityFrom<
   ViewGroupEntity,
   ViewGroupEntityRelationProperties
-> & {
-  universalIdentifier: string;
-};
+>;

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,
   };
 };