Add a new implementation of the Display Screen with websockets

[mrf345]

Is your feature request related to a problem? Please describe.
Experiencing slowness while scaling the system with +100 Display Screen active sessions.

Describe the solution you'd like
Add a new implementation of Display Screen backend and front-end which utilizes websocket protocol for realtime communication instead of typical HTTP requests. Most probably we'll use Flask-Socketio and socket.io-Client for that. This will give us a significant improvement in performance as the numbers of active sessions increase somewhere around %50 improvement for 50-100 requests and %150+ for 500-1000 requests.