Write a server supporting hq interop alpns that can serve multiple http1.0 requests based on filename paths

[mattcaswell]

Just a thought on this: quic-server-nonblock.c was designed primarily as a demo application, and as the basis for our guide page on how to write such an application. Augmenting it too far starts to make the demo more complicated than it needs to be and subvert its original intent. For that reason it might be better to create a new application specifically targeted for the interop testing purpose (which could be based initially on quic-server-nonblock.c).

[nhorman]

I've got a quic-hq-interop-server draft in https://github.com/nhorman/openssl/tree/quic-server-interop if we want to use that instead, but this is currently predicated on us implementing server version negotiation to allow our server code to work with the interoperability test harness