Need to reset the persisted save paths on load, since the file that was
loaded may have been moved since it was saved and the original location
may no longer be accessible.
Fixes https://github.com/dcs-liberation/dcs_liberation/issues/2756.
This is the first step toward bundling all assets related to a save game
into a single item. That makes it easier to avoid clobbering "temporary"
assets from other games like the state.json, but also makes it easier
for players to file bug reports, since there's only a single asset to
upload.
This is only the first step because so far it only includes the various
save files: start of turn, end of last turn before results processing,
and "latest" (the game saved explicitly by the player).