new auto confirm when paused

[Araxeus]

Old one was was heavy on resources, listened to every movement, had issue with programmatically pausing, mediakeys, etc

this new way works in a very simple way - every 15min it refreshes the internal "last activity timer" (window._lact) of youtube, and as a result the "Continue Watching?" popup never appears

youtube-music/preload.js

Lines 50 to 51 in 831b1ea

	// Blocks the "Are You Still There?" popup by setting the last active time to Date.now every 15min
	setInterval(() => window._lact = Date.now(), 900000);

Fixes #415 and Fixes #364

notes:

• this is not an optional plugin anymore since its so easy to do and I see no reason to ever disable it + plugin list is getting kinda long
• deleted song-controls-front since it was originally created only because of the old yns_pause()

[th-ch]

Looks good, thanks for this very cool improvement!