v2.19.3 Save backup + minor fixes

Introduction of a save backup system to prevent issues if a player's system crashes whilst the game is saving. Also some bug fixes reported by our [awesome!] community: - Enabled directions game words to be reviewable in the spaced repetition system (SRS). - Resolved issue where NPCs didn't spawn in the school learning environment. - Fixed the pear item so that the button can be pressed during Learning Rush on Steam Deck. Thank you!