Rewrite Modularity tests to use Perl only.
    
    The Modularity tests rely on an external script to test the modular
    behaviour of DNF. There is a potentional risk that the connection
    is be down and the script cannot be downloaded.
    
    This enhancement uses a regular OpenQA perl test case script to only
    invoke DNF commands and parse their output to test the same behaviour
    that we have been testing already.
    
    This enhancement picks a random module for each of the operations,
    and thus tries to mimick reality a little bit more.