Add a QUIC adapter

[lemunozm]

Internal adapter API docs here.

List of candidates:

• quiche mio based: example
• quinn Seems to be used on top of tokio.

[burdges]

We found quiche and the mozilla one overly specialized, so we'll adopt quinn whenever we bother making progress on this.

[kination]

@burdges just curiosity, how is quiche/mozilla one(probably neqo) is specialized? This is just a question cause I'm also interested in QUIC ... 🙏