investigate gameplayFrames

[briaguya-ai]

we're setting/resetting gameplayFrames to 0 in a few places, it'd be good to get a better grasp on when/how that happened on original hardware and if there are situations where we need to set/reset it beyond those times

from #4984 (comment):

I know this is just copying what we had before, but I figure it's worth pointing out that this is not accurate to what it is actually happening: which is that this is resetting the frame count on any play destroy with the debug save loaded (title screen or LRZ).

I think the intent for the frame reset is to happen when ever we transition from a non-PlayState game state to a PlayState game state.

Not something we need to do in this PR, but should at least track an issue for investigation (e.g. test with hardware)

#4984 (comment) (reply):

yeah, i didn't want to go down the rabbit hole of that (and autosave stuff) when moving it over (it originally came from #1792, and there's more gameplayFrames stuff in #3389 too)