Peertube events are not fired in the good order.
This is a dirty fix: saving the current window location when
initializing the chat, and comparing the saved url when navigation-end
is triggered.
* init some shared functions (videoHasWebchat, parseConfigUUIDs)
* api/room: checking that video has live enabled
* fix promise handling in initChat function
* removing some 'use strict' that are no more necessary in typescript
