feat: adjust volume on wheel

[kmcgurty]

I'm not sure if feature patches like this are welcome, but I figured if I found it useful, others might. If not, feel free to close/delete this.

This patch replicates how Spotify behaves. When you hover the volume button and scroll your mouse wheel, the volume changes up/down. It's pretty simple, and copies the logic of ctrl+up/down.

I had a bit of trouble figuring out how to know when the player loaded, but I found the window.Events.player.playerReady event useful. The renderer already subscribes to this, so I use that to add the mouse events. The actual slider is not a child of the button, so it requires 2 event subscribers. I use the aria-label to find the button - hopefully it's resistant to UI updates breaking the patch.

[josselinonduty]

Hey!
Thank you for contributing. That is indeed a nice feature to have ;)