Increase abstraction for arbitrary slot get/set operations, and fracture
SAV4 behavior for each game type.
Adds: Undo/Redo of party slot changes
Fixes: Fixed Gen5 daycare slot 2 reading, and EXP reading
Fixes: Some slot color glitchiness
Fixed: Box layout editor now hides the flag label if no flags are
present
Fixed: Gen7 box flags are now shown (unknown purpose lol)
Changed: savefile objects are generally smaller (removed a few shared
offset fields)
Remove some unnecessary properties from SaveFile
Enumerate checksum flag results for GC memcard checking
Remove unnecessary checks on savefile type
Add some documentation
Decapitalize some method parameters
