ipatests: Test deletion of required principal throws proper error
    
    ipa service-del <Principal name> did not display proper principal
    name which is being deleted in error message.
    This test check if it throws error having proper principal name.
    
    related: https://pagure.io/freeipa/issue/7695
    
    Signed-off-by: Mohammad Rizwan Yusuf <myusuf@redhat.com>
    Reviewed-By: Christian Heimes <cheimes@redhat.com>
    Reviewed-By: Rob Crittenden <rcritten@redhat.com>
    Reviewed-By: Christian Heimes <cheimes@redhat.com>