[OBJECT_CACHE_FLUSH_REQUIRED_WHEN_RELEASED] Remove FlatObjectMetadata custom fieldMetadataIds fk aggregator property (#17438)

# Introduction
Currently refactoring `flatEntity` typing, encountering some tsc errors
due to this fk aggregator custom override
It shall now follow generic pattern leading to be named `fieldIds`

Needs to flush object cache when released

packages/twenty-server/src/engine/api/common/common-args-handlers/common-query-selected-fields/common-selected-fields.handler.ts

@@ -89,7 +89,7 @@ export class CommonSelectedFieldsHandler {
         | { [key: string]: boolean | { [key: string]: boolean } };
     } = {};
 
-    for (const fieldId of flatObjectMetadata.fieldMetadataIds) {
+    for (const fieldId of flatObjectMetadata.fieldIds) {
       const field = findFlatEntityByIdInFlatEntityMapsOrThrow({
         flatEntityMaps: flatFieldMetadataMaps,
         flatEntityId: fieldId,

packages/twenty-server/src/engine/api/common/common-query-runners/common-create-many-query-runner/utils/__tests__/get-conflicting-fields.util.spec.ts

@@ -85,7 +85,7 @@ describe('getConflictingFields', () => {
       createdAt: new Date(),
       updatedAt: new Date(),
       universalIdentifier: objectMetadataId,
-      fieldMetadataIds: fields.map((f) => f.id),
+      fieldIds: fields.map((f) => f.id),
       indexMetadataIds: [],
       viewIds: [],
       applicationId: null,