streamlink-twitch-gui: initial inclusion
Summary: Closes T1410. Streamlink-twitch-gui is a NW.JS application to browse twitch.tv and open streams to your player of choice via streamlink.
Opening streams to gnome-mpv, mpv and vlc works.
Logging in with things like, your followed streams syncing, works.
Opening the chat in chatty works.
Subscribers: kyrios123, j-hdt, brutus, freddiaN
Maniphest Tasks: T1410
Differential Revision: https://dev.solus-project.com/D789