If the package set repo contains any modular package, the module
metadata is added there as well.
This is needed to accomodate change in DNF that refuses to work with
repo with modular packages if the metadata is not there. This DNF change
can cause issues in buildinstall phase.
Related: https://bugzilla.redhat.com/show_bug.cgi?id=1623128
The hybrid solver is modified to not create a separate repo with the
module metadata anymore, since it will be available in the repo with
packages. This also allows us to drop code to look into lookaside repos.
We still need to iterate over local modules in order to find out what
platform should be used.
JIRA: COMPOSE-3621
Signed-off-by: Lubomír Sedlář <lsedlar@redhat.com>