Merge branch 'toger5/connectionLostBanner' into connectionlostbanner_lk

NB. I had to more or less rewrite this as it had been refactored in the livekit branch.

public/locales/en-GB/app.json

@@ -25,6 +25,8 @@
   "Change layout": "Change layout",
   "Close": "Close",
   "Confirm password": "Confirm password",
+  "Connection lost": "Connection lost",
+  "Connectivity to the server has been lost.": "Connectivity to the server has been lost.",
   "Copied!": "Copied!",
   "Copy": "Copy",
   "Copy and share this call link": "Copy and share this call link",