ipatests: add integration test checking the files mode
    
    The test runs rpm -V in order to check that the file
    permissions are consistent with the expectations set
    in the spec file. The file mode, owner and group are
    checked.
    
    Related to https://pagure.io/freeipa/issue/7934
    
    Reviewed-By: Rob Crittenden <rcritten@redhat.com>
    Reviewed-By: Christian Heimes <cheimes@redhat.com>