this commit also remove all the sonic envelope parsing and reintroduces filters in REQ as a slice instead of as a singleton.
why? well, the sonic stuff wasn't really that fast, it was a little bit but only got fast enough once I introduced unsafe conversions between []byte and string and did weird unsafe reuse of []byte in order to save the values of tags, which would definitely cause issues in the future if the caller wasn't aware of it (and even if they were, like myself).
and the filters stuff is because we abandoned the idea of changing NIP-01 to only accept one filter per REQ.
- make BatchedSubManyEose() use a single duplicate id index and use it for replaceable loaders;
- fixes parsing follow entry from kind:3 events (and others);
- adds a "cause" to most cancelation errors in relay/pool;
- remove the inherent cache from dataloader (we have our own hopefully);
- increase max frame size we can read from any websocket to 2**18 (262k), which gives over 2000 item lists.
We replace the bare websocket.Conn type with a new Connection type which
implements `WriteJSON`, `WriteMessage`, and `Close`. The Connection
type adds mutexes around writes since gorilla doesn't support concurrent
writes to websockets.
Signed-off-by: Honza Pokorny <honza@pokorny.ca>
