Object metadata API create one using workspace migration v2 (#13420)

# Introduction
In this PR we create basic transpilation methods and utils to handle
input to flat, entity to flat, object maps to flat. In order to
transpile everything into a common validation that will be implemented
in another PR

## FieldMetadataEntity typing
Added `never | null` to fields that should never be in order to ease
general abstracted method to pass null, as anw it's what is in the
database

## Todo
- ~~Create a feature flag~~
- Integration test for object creation through metadata api + pg col
introspection and snapshoting

packages/twenty-server/src/engine/workspace-manager/dev-seeder/core/utils/seed-feature-flags.util.ts

@@ -60,6 +60,11 @@ export const seedFeatureFlags = async (
         workspaceId: workspaceId,
         value: true,
       },
+      {
+        key: FeatureFlagKey.IS_WORKSPACE_MIGRATION_V2_ENABLED,
+        workspaceId: workspaceId,
+        value: false,
+      },
     ])
     .execute();
 };