Add revoke

[lublak]

https://dev.twitch.tv/docs/authentication/revoke-tokens/

[kanimaru]

A cool feature. When someone has time we could put it into the new Twitcher Settings window. Probably just to the (Remove Token) Button in there. I think that would be the right place.

[lublak]

@kanimaru For me, it will be an application that several users will be able to use. That's why I'll simply add the deletion of the token myself later, a rewoke would of course be even nicer here. Of course, it also makes sense in the setting. (But I hardly use them here because I want it to work standalone afterwards, of course; without godot editor).