WIP: Extended ini support

[ZashIn]

Extends ini support with optional:

• [x] [Features]
  • [x] LocalSavegames = True (defaults to game.savesDirectory()) or custom path
  • [x] SaveGamePreview = path to img
    • [ ] Add %SAVE_NAME% variable for e.g. %SAVE_NAME%.png
  • [ ] ForceLoadLibraries = list of .dll files
• [x] [BasicModDataChecker] and [BasicModDataChecker.move]
• [x] uses ExtendedInterpolation to support e.h. {BasicGames.key} substitution
• [ ] Add BasicGames.GameSaveAdditionalFiles as simple option for ISaveGame.allFiles, with %SAVE_NAME% var
• [ ] Add subfolder globbing */*.ext to BasicModDataChecker (requires larger changes in another PR)
• [x] Add template .ini file: game_template.ini

This would allow users without python knowledge to add a game support with some basic features or provide a good base for devs to add required functionality in python.