Latency measurements.

[Ocean50ul]

We need to add latency measurements.

1. Audio back-end latency (time between cpal throws enough PCMs to encode single 20ms frame, and encoder done its job). SHOULD BE QUITE LOW.
2. Time between Rust socket.write() and python's reader.read() (sanity check for the code I've made). SHOULD BE ALMOST INSTANT
3. Time between python's reader.read() and websocket.send() (again, sanity check). SHOULD BE ALMOST INSTANT
4. Latency between python server and client device (ping-pong test). DEPENDS ON THE NETWORK CONNECTION
5. Clients side decoding latency (time between recv the frame and decoder done its job). DEPENDS ON THE BUFFER CONFIGURATION