trusts: Detect domain clash with IPA domain when adding a AD trust
    
    When IPA is deployed in the same domain as AD, trust-add fails since
    the names of the local domain and trusted domain ranges is the same
    - it's always DOMAIN.NAME_id_range.
    
    When adding a trusted domain, we look for previous ranges for
    this domain (which may have been left behind by previous trust
    attempts). Since AD and IPA are in the same domain, we find
    a local domain range, which does not have a SID.
    
    Detect such domain collisions early and bail out with an appropriate
    error message.
    
    https://fedorahosted.org/freeipa/ticket/4549
    
    Reviewed-By: Martin Babinsky <mbabinsk@redhat.com>