This is a hacky implementation of WebSocket server, embedded into our
postgres proxy. The server is used to allow https://github.com/neondatabase/serverless
to connect to our postgres from browser and serverless javascript functions.
How it will work (general schema):
- browser opens a websocket connection to
`wss://ep-abc-xyz-123.xx-central-1.aws.neon.tech/`
- proxy accepts this connection and terminates TLS (https)
- inside encrypted tunnel (HTTPS), browser initiates plain
(non-encrypted) postgres connection
- proxy performs auth as in usual plain pg connection and forwards
connection to the compute
Related issue: #3225
