Use an RPC/Serialization framework to encode messages over WebSocket

[SdtElectronics]

Currently, the client and the server talk a primitive protocol with a single-byte header and the payload over the WebSocket connection. In the future, advanced features require exchanging messages with more complex structures. A dedicated RPC/Serialization framework can make this easier to implement and maintain.

Goals:

• Refactor the backend to further decouple the protocol from the service logic
• Incorporate a dedicated RPC/Serialization framework
• Rewrite the frontend and the backend to implement the protocol above the framework