Split modular repos to the separate packages
    
    Since modular repos do not contain any defaults (and most likely will
    not in the near future) and slow-down (even though just a bit) DNF,
    there is no point in shipping them on by default. However, anybody who
    is interested in them, cam install fedora-repos-modular and get all the
    content from there. Those repos are still enabled by default as long as
    you have a package installed.
    
    References: https://pagure.io/fesco/issue/2114
    Signed-off-by: Igor Raits <ignatenkobrain@fedoraproject.org>