Updates the room API to use `extraFields` instead of `expand` for including additional data in responses.
This change improves clarity and consistency in the API design.
It also simplifies the filtering logic by explicitly differentiating between
base fields (controlled by `fields`) and extra fields (controlled by `extraFields`).
The changes include:
- Renaming the query parameter and header
- Updating the validation schemas
- Adjusting the filtering logic in the controller and service layers
- Updating the frontend components and services
