Improve user experience when authentication session expires

[ericleponner]

Problem

When authentication expires, TT displays error toast below:

TT should avoid talking about refreshing the page : this makes sense in a browser but not in TT.

Solution

• Today the only solution for user is to exit and restart TT. So a better message would be:
  Try restart the app and signing in again

• Even better, TT should cleanly disconnect user and display login dialog.