Move systemd-oomd-defaults into specific environment groups
    
    It is removed from @core, and added to @cloud-server, @gnome-desktop,
    @kde-desktop, @server-product, @workstation-product instead.
    
    My understanding is that both KDE and GNOME use cgroups and work
    nicely with systemd-oomd, and cloud and server should be fine with it
    too. The environments that use those groups previously included
    systemd-oomd-defaults from @core, so this change should not add
    systemd-oomd-defaults to anything, but remove it from the groups and
    environments that don't include the five groups that now reference it.
    
    Fixes https://pagure.io/fedora-comps/issue/737.
    
    Not tested.