[dns-operations] HTTPS record support

[Florian Weimer]

* Andrew Latham:

> Can you share a link to the ticket or RFE here?

Here's one:

  SVCB and HTTPS RR should have protocol independent API
  <https://issues.redhat.com/browse/RHEL-58720>

It's worded as requesting a new API in addition to getaddrinfo, but
that's really not where I want to go.

There is an related upstream ticket for the older SRV record:

  Support for SRV records in getaddrinfo 
  <https://sourceware.org/bugzilla/show_bug.cgi?id=2099>

Thanks,
Florian