synthesize a HTTPS record for pi.hole - #2988

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What does this PR aim to accomplish?:

FTL now includes native HTTP/2 and HTTP/3 support, it makes sense to advertise those capabilities via DNS, more specifically the HTTPS RR. Modern browsers are already querying for it in addition to A/AAAA. This allows them to connect directly using QUIC instead of upgrading later.

How does this PR accomplish the above?:

This PR adds an automatically synthesized RFC 9460 HTTPS RR for pi.hole. if any native TLS listener is active.
example:

1 . alpn="h2,h3" port=8086 ipv4hint=127.0.0.1 ipv6hint=::1

alpn is decided based on compile-time support.
The IP hints are localized and match the A/AAAA data.

Limitation I am working on:

This currently doesn't work with CNAMEs targeting pi.hole. It is not as simple as #2585, since dnsmasq's cache differs for host (A/AAAA) and generic Resource Records.

Link documentation PRs if any are needed to support this PR:

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