When LDAP is enabled:
- create_role: creates LDAP group before DB record
- update_role: renames LDAP group before DB update
- delete_role: deletes LDAP group before DB deletion
- assign_role: adds to LDAP group before creating RoleAssignment
- revoke_role: removes from LDAP group before deactivating assignment
On LDAP error: operation fails, no DB changes
On DB error after LDAP success: rollback LDAP changes
Fixes: roles could bypass LDAP when it was enabled