Draft: Random button on character select

Adds the ability to randomize all non-profile options on character select by holding Z. Functionality is included to allow for rapid-fire randomization of any and all options by holding Z+A. A check is included to ensure that the randomization does not select an empty grid slot. Additionally, a function is included to cycle through the item roulette sounds while randomizing (with thanks to frivolousaqua on Discord for the suggestion).

Currently marked as a draft due to a bug where holding Z+A will incorrectly play the attack sound of the previously highlighted character instead of the actual selected character. This is currently the only outstanding issue I've identified. ringracers0017