Allow automatic updates for "position in queue"
Closes #98 (closed)
- Creates lab_view.js which makes the websocket connection and intercepts the updates
 - adds a method to NotificationService to update the position
 - refactors, renames and documents the related methods in RequestService
 - reloads the lab view page when the student becomes 0th in the queue (their request starts being processed)
 
Edited  by Sára Juhošová