resolved: do DNS RR type based routing

resolved: do DNS RR type based routing

So far we only looked at the domain name when routing requests to
specific scopes. With this we'll also take the DNS RR type into account.
This takes benefit of the fact that lookups for RRs such as SOA or NS or
the various DNSSEC RR types never really make sense to be routed to
LLMNR or mDNS, since they don't have concepts there.

This hence refuses to route requests for those RR types to the
LLMNR/mDNS scopes, which hence means they'll likely be routed to classic
DNS instead.

This should improve behaviour of tools that assumes it speaks to classic
DNS only via 127.0.0.53, since it will now usually do that.