Manage user timezone in keycloak

In our Drupal websites, we currently have a setting enabled that updates a user's timezone based on the value stored in Keycloak.

However, at the moment, Keycloak does not provide a field where users can set their timezone. As a result, users have no way of managing their timezone directly in Keycloak, which defeats the purpose of syncing it to Drupal.

To address this, we should:

• Add a timezone field to Keycloak, allowing users to manage their timezone directly from their Keycloak profile.
• Update the Drupal user edit form to include a link pointing to the relevant Keycloak page where the user can edit their timezone.

Action Items

• Add a timezone field to the user profile in Keycloak.
• Ensure the field is editable by the user in the Keycloak UI.
• Update the Drupal user edit form to:
  • Remove or disable timezone editing.
  • Add a help text or link directing users to Keycloak to manage their timezone.
• Test the sync between Keycloak and Drupal to ensure the timezone is correctly pulled and applied.

/cc @cguindon