Link between staff and idir user

**Overview**
Staff are the primary users of Track application. All the staff users are supposed to have an IDIR prior to sign in the Track.
**Things to do**
1. Create a column idir_user_id in staff table
2. Copy the provider_id from keycloak based on the staff email address
3. Need a migration to fix the idir_user_id for the existing staff members