Debug panel for WebSockets

[filmor]

It would be extremely useful if this would include an option to show all currently open websockets, and the data that was exchanged with some client information. Furthermore, in general, it would be nice to inject data (like runtime of a background worker) into this.

Any pointers on how to achieve this?

[asvetlov]

All these features require new aiohttp signals for hooking websocket behavior at least.