[FEATURE REQUEST] Make movie sync settings temporary and not overwritting current settings

Hello, when playing a game on a core with specific settings but you want to play back a TAS with different settings, your settings will be overwriten and won't come back to your current settings when stopping the movie.

It would be cool to make settings from a movie played back to be temporary, then you don't lose your settings. I know that there is the load and save feature, but when you have to change your settings multiple times, you don't think about saving them.
Also, to prevent another problem, if you played back a movie and you quit BizHawk just after. It would means that the "movie mode" needs to be disabled and so your normal settings will be replaced and kept for the next time.

Thanks !

Start by tracing how movie playback applies settings and how movie mode is disabled when playback ends or BizHawk exits. Define how the existing settings should be preserved and restored, then identify the relevant implementation and tests; the issue names no files or entry points, so the scope needs repository research first.