fix precise-volume hud positioning

[Araxeus]

This change was needed for 2 reasons:

• Video.clientHeight update delay on srcChanged event:
  

  youtube-music/plugins/video-toggle/front.js

  Line 43 in 89ea66b

  video.addEventListener('srcChanged', videoStarted);

  
  the following code was supposed to position the hud, but video.clientHeight was 0 (because it wasn't updated yet)
  

  youtube-music/plugins/video-toggle/front.js

  Line 96 in 89ea66b

  volumeHud.style.top = showVideo ? `${(player.clientHeight - video.clientHeight) / 2}px` : 0;

  
  fixed by setting a tiny delay (250ms) before changing the hud position

---

• hud sometimes mispositioned when video-toggle is off:
  the active hud positioning was only inside the video-toggle plugin, so I moved it to the precise-volume plugin.
  now if video-toggle is enabled - it will handle all hud positioning, and if it isn't, then precise-volume will handle it itself

[th-ch]

Looks ok, thanks for the improvement! ✅