Deprecate object metadata maps in favor of flat entities (#16080)

## Context
Deprecating the old objectMetadataMap type in favour of split flat
entities to match with our new caching.
In the long run, trying to achieve:
- Better performance through caching
- Consistent data access patterns across the codebase
- Reduced database queries

Now that everything is based on flat entities, which are cached, we can
finish the refactoring of workspace context cache which should already
improve performances.
Then the last step will be to consume that new cache in the new global
datasource to get rid of the many workspace datasources stored in the
server

packages/twenty-server/src/engine/metadata-modules/object-permission/field-permission/field-permission.service.ts

@@ -14,9 +14,10 @@ import {
 } from 'src/engine/core-modules/graphql/utils/graphql-errors.util';
 import { FieldMetadataEntity } from 'src/engine/metadata-modules/field-metadata/field-metadata.entity';
 import { isFieldMetadataTypeRelation } from 'src/engine/metadata-modules/field-metadata/utils/is-field-metadata-type-relation.util';
-import { createEmptyFlatEntityMaps } from 'src/engine/metadata-modules/flat-entity/constant/create-empty-flat-entity-maps.constant';
+import { type FlatEntityMaps } from 'src/engine/metadata-modules/flat-entity/types/flat-entity-maps.type';
 import { WorkspaceManyOrAllFlatEntityMapsCacheService } from 'src/engine/metadata-modules/flat-entity/services/workspace-many-or-all-flat-entity-maps-cache.service';
-import { buildObjectMetadataItemWithFieldMaps } from 'src/engine/metadata-modules/flat-object-metadata/utils/build-object-metadata-item-with-field-maps.util';
+import { type FlatFieldMetadata } from 'src/engine/metadata-modules/flat-field-metadata/types/flat-field-metadata.type';
+import { type FlatObjectMetadata } from 'src/engine/metadata-modules/flat-object-metadata/types/flat-object-metadata.type';
 import { type UpsertFieldPermissionsInput } from 'src/engine/metadata-modules/object-permission/dtos/upsert-field-permissions.input';
 import { FieldPermissionEntity } from 'src/engine/metadata-modules/object-permission/field-permission/field-permission.entity';
 import {
@@ -25,7 +26,6 @@ import {
   PermissionsExceptionMessage,
 } from 'src/engine/metadata-modules/permissions/permissions.exception';
 import { RoleEntity } from 'src/engine/metadata-modules/role/role.entity';
-import { type ObjectMetadataMaps } from 'src/engine/metadata-modules/types/object-metadata-maps';
 import { WorkspacePermissionsCacheService } from 'src/engine/metadata-modules/workspace-permissions-cache/workspace-permissions-cache.service';
 
 @Injectable()
@@ -70,18 +70,6 @@ export class FieldPermissionService {
         },
       );
 
-    const objectMetadataMapsById: ObjectMetadataMaps['byId'] = {};
-
-    for (const [id, flatObj] of Object.entries(flatObjectMetadataMaps.byId)) {
-      if (isDefined(flatObj)) {
-        objectMetadataMapsById[id] = buildObjectMetadataItemWithFieldMaps(
-          flatObj,
-          flatFieldMetadataMaps,
-          createEmptyFlatEntityMaps(),
-        );
-      }
-    }
-
     const existingFieldPermissions = await this.fieldPermissionsRepository.find(
       {
         where: {
@@ -97,7 +85,8 @@ export class FieldPermissionService {
       this.validateFieldPermission({
         allFieldPermissions: input.fieldPermissions,
         fieldPermission,
-        objectMetadataMapsById,
+        flatObjectMetadataMaps,
+        flatFieldMetadataMaps,
         rolesPermissions,
         role,
       });
@@ -193,13 +182,15 @@ export class FieldPermissionService {
   private validateFieldPermission({
     allFieldPermissions,
     fieldPermission,
-    objectMetadataMapsById,
+    flatObjectMetadataMaps,
+    flatFieldMetadataMaps,
     rolesPermissions,
     role,
   }: {
     allFieldPermissions: UpsertFieldPermissionsInput['fieldPermissions'];
     fieldPermission: UpsertFieldPermissionsInput['fieldPermissions'][0];
-    objectMetadataMapsById: ObjectMetadataMaps['byId'];
+    flatObjectMetadataMaps: FlatEntityMaps<FlatObjectMetadata>;
+    flatFieldMetadataMaps: FlatEntityMaps<FlatFieldMetadata>;
     rolesPermissions: ObjectsPermissionsByRoleId;
     role: RoleEntity;
   }) {
@@ -230,10 +221,10 @@ export class FieldPermissionService {
       );
     }
 
-    const objectMetadataForFieldPermission =
-      objectMetadataMapsById[fieldPermission.objectMetadataId];
+    const flatObjectMetadata =
+      flatObjectMetadataMaps.byId[fieldPermission.objectMetadataId];
 
-    if (!isDefined(objectMetadataForFieldPermission)) {
+    if (!isDefined(flatObjectMetadata)) {
       throw new PermissionsException(
         PermissionsExceptionMessage.OBJECT_METADATA_NOT_FOUND,
         PermissionsExceptionCode.OBJECT_METADATA_NOT_FOUND,
@@ -243,7 +234,7 @@ export class FieldPermissionService {
       );
     }
 
-    if (objectMetadataForFieldPermission.isSystem === true) {
+    if (flatObjectMetadata.isSystem === true) {
       throw new PermissionsException(
         PermissionsExceptionMessage.CANNOT_ADD_FIELD_PERMISSION_ON_SYSTEM_OBJECT,
         PermissionsExceptionCode.CANNOT_ADD_FIELD_PERMISSION_ON_SYSTEM_OBJECT,
@@ -253,12 +244,10 @@ export class FieldPermissionService {
       );
     }
 
-    const fieldMetadataForFieldPermission =
-      objectMetadataForFieldPermission.fieldsById[
-        fieldPermission.fieldMetadataId
-      ];
+    const flatFieldMetadata =
+      flatFieldMetadataMaps.byId[fieldPermission.fieldMetadataId];
 
-    if (!isDefined(fieldMetadataForFieldPermission)) {
+    if (!isDefined(flatFieldMetadata)) {
       throw new PermissionsException(
         PermissionsExceptionMessage.FIELD_METADATA_NOT_FOUND,
         PermissionsExceptionCode.FIELD_METADATA_NOT_FOUND,