Fix broken data model translation (#13067)

In this PR, I'm fixing a bug introduced in recent performance work on
the cache.

Bug context: https://github.com/twentyhq/twenty/issues/12865
Related PR opened by a contributor:
https://github.com/twentyhq/twenty/pull/13003

## Root cause

We cache all objectMetadataItems at graphql level : see
`useCachedMetadata` hook:
- instead of going through the regular resolvers, we direlcty load data
from the cache. However this data must be localized regarding labels and
descriptions

In a precedent refactoring, we introduced the notion of locale in the
cache key. However, the user locale was not properly taken into account
as we did not have the information in this hook.

## Fix

1. **Introduce locale in userWorkspace entity**. The locale is stored on
workspaceMember in each postgres workspaceSchema (workspace_xxx) which
is the alter ego of userWorkspace in postgres core schema. Note that we
can't store it in user as a user can be part of multiple workspaces (the
locale already there must be seen as a default for this user), and we
cannot rely on workspaceMember as we would need to query the
workspaceSchema in the authentication layer which we want to avoid for
performance reasons.

2. During request hydration from token (containing the userWorkspaceId),
we fetch the userWorkspace and store it in the Request (this impact both
AuthContext and Request interface)

3. Leverage userWorkspace.locale in the useCachedMetadata hook

## Additional notes

There is no need to change the way we store and retrieve the
object-metadata-maps object itself which is different from the graphql
layer cache. object-metadadata-maps are not localized

packages/twenty-server/src/database/typeorm/core/migrations/common/1751700932529-add-locale-to-user-workspace.ts

@@ -0,0 +1,19 @@
+import { MigrationInterface, QueryRunner } from 'typeorm';
+
+export class AddLocaleToUserWorkspace1751700932529
+  implements MigrationInterface
+{
+  name = 'AddLocaleToUserWorkspace1751700932529';
+
+  public async up(queryRunner: QueryRunner): Promise<void> {
+    await queryRunner.query(
+      `ALTER TABLE "core"."userWorkspace" ADD "locale" character varying NOT NULL DEFAULT 'en'`,
+    );
+  }
+
+  public async down(queryRunner: QueryRunner): Promise<void> {
+    await queryRunner.query(
+      `ALTER TABLE "core"."userWorkspace" DROP COLUMN "locale"`,
+    );
+  }
+}