## Problem
I wanted to do a deep dive of the tungstenite codebase.
tokio-tungstenite is incredibly convoluted... In my searching I found
[fastwebsockets by deno](https://github.com/denoland/fastwebsockets),
but it wasn't quite sufficient.
This also removes the default 16MB/64MB frame/message size limitation.
framed-websockets solves this by inserting continuation frames for
partially received messages, so the whole message does not need to be
entirely read into memory.
## Summary of changes
I took the fastwebsockets code as a starting off point and rewrote it to
be simpler, server-only, and be poll-based to support our Read/Write
wrappers.
I have replaced our tungstenite code with my framed-websockets fork.
<https://github.com/neondatabase/framed-websockets>
## Problem
We have no regression tests for websocket flow
## Summary of changes
Add a hacky implementation of the postgres protocol over websockets just
to verify the protocol behaviour does not regress over time.
