mdns: T5615: Allow controlling IP version to use for mDNS repeater
This commit adds a new configuration option to the mDNS repeater service
to allow controlling which IP version to use for mDNS repeater.
Additionally, publishing AAAA record over IPv4 and A record over IPv6 is
disabled as suggested.
See:
- https://github.com/lathiat/avahi/issues/117#issuecomment-1651475104
- https://bugzilla.redhat.com/show_bug.cgi?id=669627#c2
(cherry picked from commit e66f7075ee12ae3107d29efaf683442c3535e8b9)