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).

While I have yet to identify the cause of a bug that makes it so the sound of the previously highlighted character or follower will be played instead of the actual selected character when rapidly randomizing selections, I'm unfortunately still at a loss as to how to address the bug. The primary reason I am unmarking this as a draft is because plans to expand on this feature seem to go out of desirable scope, going by discussion with Toaster, and I genuinely am not sure how to actually address the sound bug. This bug does not impact any of the core functionality of the feature, simply playing an incorrect sound while still selecting everything correctly, nor does it cause any regressions in existing functionality, and so after some thought, I'm going to go ahead and un-draft this for review. If a solution to the bug is found at a later point prior to final review, I will commit it to the branch (or welcome someone else finding it and submitting the commit) - otherwise, I think this is about as ready for review as I can currently get it. ringracers0017