quic: add quic

Working on adding QUIC back. This is a bit of a rewrite of the original and is not yet complete (thus the draft status).

There are several important bits here:

1. The internal classes are Endpoint, EndpointWrap, Session, and Stream (originally these were named QuicSocket, QuicSession, and QuicStream.

2. Endpoint and EndpointWrap are a bit special...

• Endpoint wraps a uv_udp_t but does not wrap UDPWrap. The reason is to give us finer control over how the UDP port is used and configured, and how data flows.
• EndpointWrap is the JS Wrapper object around Endpoint. It is designed to be cloneable via MessagePort. What that means is that an Endpoint (and it's associated uv_udp_t can essentially be shared across multiple worker threads while still being owned by a single event loop). It makes the implementation a bit more complicated but opens up the ability for processing QUIC sessions across multiple worker threads.

3. Stream is no longer a StreamBase. In fact, while the QUIC implementation will be capable of sending from a Readable stream, and will support being read as a Readable, the QUIC JavaScript Stream object will not be a Node.js stream object. This is a major API change from the original implementation. More details on this later, but the usage pattern will be closer to what we see in browser environments (e.g. stream.blob(), stream.readable(), stream.text(), etc).

4. There's no only partial JS API exposed here yet. That's coming as I work through the rewrite.