Refactor FieldMetadataService and validation to consume FlatObjectMetadataMaps (#13719)

# Introduction
Following recent `FlatObjectMetadataMaps` manipulation, transpilers
utils introduction in https://github.com/twentyhq/twenty/pull/13620
Refactored the field metadata service and validator to iterate over
`FlatObjectMetadataMaps` instead of `FlatObjectMetadata[]`.

The object metadata service v2 is shadow coding

packages/twenty-server/src/engine/metadata-modules/flat-object-metadata/utils/from-flat-object-metadata-maps-to-flat-object-metadatas.util.ts

@@ -0,0 +1,13 @@
+import { isDefined } from 'twenty-shared/utils';
+
+import { FlatObjectMetadataMaps } from 'src/engine/metadata-modules/flat-object-metadata-maps/types/flat-object-metadata-maps.type';
+import { FlatObjectMetadata } from 'src/engine/metadata-modules/flat-object-metadata/types/flat-object-metadata.type';
+import { fromFlatObjectMetadataWithFlatFieldMapsToFlatObjectMetadata } from 'src/engine/metadata-modules/flat-object-metadata/utils/from-flat-object-metadata-with-flat-field-maps-to-flat-object-metadatas.util';
+
+export const fromFlatObjectMetadataMapsToFlatObjectMetadatas = (
+  flatObjectMetadataMaps: FlatObjectMetadataMaps,
+): FlatObjectMetadata[] => {
+  return Object.values(flatObjectMetadataMaps.byId)
+    .filter(isDefined)
+    .map(fromFlatObjectMetadataWithFlatFieldMapsToFlatObjectMetadata);
+};

packages/twenty-server/src/engine/metadata-modules/flat-object-metadata/utils/from-flat-object-metadata-to-flat-object-metadata-with-flat-field-maps.util.ts

@@ -8,6 +8,8 @@ export const fromFlatObjectMetadataToFlatObjectMetadataWithFlatFieldMaps = (
   const emptyFlatObjectMetadataWithFlatFieldMaps: FlatObjectMetadataWithFlatFieldMaps =
     {
       ...flatObjectMetadata,
+      flatIndexMetadatas: [],
+      flatFieldMetadatas: [],
       fieldIdByJoinColumnName: {},
       fieldIdByName: {},
       fieldsById: {},

packages/twenty-server/src/engine/metadata-modules/flat-object-metadata/utils/from-object-metadata-maps-to-flat-object-metadatas.util.ts

@@ -1,18 +0,0 @@
-import { isDefined } from 'twenty-shared/utils';
-
-import { FlatObjectMetadata } from 'src/engine/metadata-modules/flat-object-metadata/types/flat-object-metadata.type';
-import { fromObjectMetadataItemWithFieldMapsToFlatObjectMetadata } from 'src/engine/metadata-modules/flat-object-metadata/utils/from-object-metadata-item-with-field-maps-to-flat-object-metadata.util';
-import { ObjectMetadataMaps } from 'src/engine/metadata-modules/types/object-metadata-maps';
-
-export const fromObjectMetadataMapsToFlatObjectMetadatas = (
-  objectMetadataMaps: ObjectMetadataMaps,
-): FlatObjectMetadata[] => {
-  return Object.values(objectMetadataMaps.byId)
-    .filter(isDefined)
-    .map((objectMetadataItemWithFieldMaps) =>
-      fromObjectMetadataItemWithFieldMapsToFlatObjectMetadata({
-        objectMetadataItemWithFieldMaps,
-        objectMetadataMaps,
-      }),
-    );
-};