* Users: add is_disabled column
* Users: disable users removed from LDAP
* Auth: return ErrInvalidCredentials for failed LDAP auth
* User: return isDisabled flag in user search api
* User: mark disabled users at the server admin page
* Chore: refactor according to review
* Auth: prevent disabled user from login
* Auth: re-enable user when it found in ldap
* User: add api endpoint for disabling user
* User: use separate endpoints to disable/enable user
* User: disallow disabling external users
* User: able do disable users from admin UI
* Chore: refactor based on review
* Chore: use more clear error check when disabling user
* Fix login tests
* Tests for disabling user during the LDAP login
* Tests for disable user API
* Tests for login with disabled user
* Remove disable user UI stub
* Sync with latest LDAP refactoring
