quic: support AbortSignal in QuicSocket connect/listen
This builds on #34865, which must land first (the first five commits are from that PR)
This does two things:
- Minor cleanups on http3 native internals
- Adds support for AbortSignal in QuicSocket connect and listen
Checklist
-
make -j4 test
(UNIX), orvcbuild test
(Windows) passes -
tests and/or benchmarks are included -
documentation is changed or added -
commit message follows commit guidelines