Enhancement: Allow note hit flash effects to display for opposing side

[waspennator]

Please check for duplicates or similar issues before creating this issue.

What is your suggestion, and why should it be implemented?

It would honestly look much better visually and better prep the game for the inevitable 2 player mode if the opponent's side has the same effect for hitting the notes visually like player 1's side. (Mostly cause the arrows on the opponent side just simply vanish once they hit the ones on top)