WebSocket communication noise

[mversic]

For data streaming we use websocket communication protocol over which we overly our own. Our communication protocol over an already established websocket for both events and block streaming (the only two we currently have) looks like this:

1. client sends an event stream subscription request with all the details
2. server responds with subscription accepted message
3. server starts streaming events:
   3.1 server sends an event
   3.2 client responds with the event received message

Both the subscription accepted message and the event received message are redundant because they don't influence the control flow in any way and the fact that the message was received is guaranteed in the lower layers of abstraction as in TCP. While subscription accepted message is sent only once event received incurs a useless communication latency and should be removed.

[appetrosyan]

I suppose the answer lies in what can be sent as a receipt, and if we can encode the lower-level receipt as a higher-level control flow primitive.