support more connectors

[darkskygit]

In OctoBase, the sync protocol is designed to be transport layer agnostic.

Developers only need to provide an mpsc sender and receiver to transmit data in different transport layers.

For example, we can simply bind ydoc, and monitor its read and write, we accept update from mpsc receiver, and send the modification of ydoc to sender, so as to realize an in-memory connector.

We can use the in-memory connector to simulate multi-person collaboration without the need to build a complex server environment.

Similarly, we can implement more connectors based on http, webrtc or libp2p, so that octobase can be easily synchronized in different network environments.

The planned connector:

### Tasks
- [x] in-memory connector #286
- [x] websocket connector #428
- [ ] libp2p connector
- [ ] https://github.com/toeverything/OctoBase/issues/431
- [ ] https://github.com/toeverything/OctoBase/issues/433
- [ ] http event stream (like chatgpt)