cert-request: collect only qualified DNS names for IPAddress validation
    
    Collect only qualified DNS names for IPAddress validation.  This is
    necessary because it is undecidable whether the name 'ninja' refers
    to 'ninja.my.domain.' or 'ninja.' (assuming both exist).  Remember
    that even a TLD can have A records.
    
    Now that we are only checking qualified names for the purpose of
    IPAddressName validation, remove the name length hack from
    _san_dnsname_ips().
    
    Part of: https://pagure.io/freeipa/issue/7451
    
    Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>
    Reviewed-By: Florence Blanc-Renaud <frenaud@redhat.com>