MINOR: quic: support hq-interop

Implement a new app_ops layer for quic interop. This layer uses HTTP/0.9
on top of QUIC. Implementation is minimal, with the intent to be able to
pass interoperability test suite from
https://github.com/marten-seemann/quic-interop-runner.

It is instantiated if the negotiated ALPN is "hq-interop".
4 files changed