Use msgpack for API

[nezuo]

Switches the rojo API to use msgpack instead of JSON.

Fixes #363.
Fixes #881.

[nezuo]

JJ doesn't support git submodules 😢

[nezuo]

I'm not sure if the tests are correct because some tests seem to run infinitely.

There is also this code in serve_utils that uses json. Not sure what this is for or if it needs to be updated.

Ok(Message::Text(text)) => {
                    let packet: SocketPacket = serde_json::from_str(&text)?;
                    if packet.packet_type != packet_type {
                        continue;
                    }

                    // Close the WebSocket connection now that we got what we were waiting for
                    let _ = socket.close(None);
                    return Ok(packet);
                }

EDIT: Fixed

[nezuo]

The protocolVersion will have to be bumped if this is not included in the upcoming release.

[Quenty]

spare print statement you may want to remove

[nezuo]

good catch, thanks.

[Quenty]

Note: There's weird failure modes for when plugin/rojo are out of sync here.

[Dekkonot]

I merged another change to the web API without thinking about the impact on this PR but this looks good to me.

[nezuo]

Tests pass on my machine, not sure what happened.