idview: add domain_resolution_order attribute
    
    `idview-add` and `idview-mod` can now set and validate the attribute.
    The required objectclass is added on-demand after modification
    
    https://pagure.io/freeipa/issue/6372
    
    Reviewed-By: Martin Basti <mbasti@redhat.com>
    Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>
    Reviewed-By: Jan Cholasta <jcholast@redhat.com>