* For anonymous users: new "log in using an external account" dialog, with the "remote Peertube account" options
* ConverseJS: using global vars for custom localized string (injected
using Webpack)
* Fullscreen chat: now uses a custom page (in other words: when opening the chat in a new tab, you will have the Peertube menu). WIP
* some code refactoring (getBaseRoute moved to util/uri, ...)