ovirt-foreign-menu: Fetch host, cluster and data center information
    
    It is possible that the data center the VM is associated with has more
    than one storage domain associated with it as well, when only one is
    active while the others are not.
    
    The current ovir-foreign-menu code does not take it into consideration,
    thus the ISO dialog may show invalid results with that scenario. We fix
    this problem by making use of new functions in libgovirt, adding support
    or hosts, clusters and data centers.
    
    Related: https://bugzilla.redhat.com/show_bug.cgi?id=1427467
             https://bugzilla.redhat.com/show_bug.cgi?id=1428401
    
    Signed-off-by: Eduardo Lima (Etrunko) <etrunko@redhat.com>