Dock to sidebar breaks group and timestamp hotkey

[aidenlx]

If I link the player with a note, then move the player to the sidebar, it's no longer linked and the timestamp hotkey doesn't work

If I get the chance I can try to fix that, but I'm guessing it might require substantial changes behind the scenes since Obsidian just doesn't allow linking sidebar panes.

Maybe media-extended could store a reference to the most recently focused player and default to using that for timestamps when a pane isn't linked.

Originally posted by @geoffreysflaminglasersword in https://github.com/aidenlx/media-extended/issues/66#issuecomment-894671011