Create versioning system for .story files

[Atlinx]

Store a variable in .story files called "version" which will be an integer. Developers will be able to set the version to whatever they want, and the intended workflow is to increment version every time developers release a modified version of the same story file. Then when loading a save slot, StorySaveManager will first check to see if the version from both the save slot and the slot's save file are the same before attempting to load the save file.

A feature like this would allow developers to modify their stories after shipping their game by letting FracturalVNE detect if a save file is loadable and avoids simply crashing the game if the user loads an unloadable save slot.