[Feature] Adding game save/load callbacks for lua scripting.

Закрыто xottab-duty запросил слияние github/fork/Neloreck/feature/game-saves-callbacks в dev

Created by: Neloreck

Adding optional lua callbacks to allow creation of custom saves. Following same pattern as CoC/anomaly mods. Having marshal library without these callbacks does not make complete sense because NetPacket has size limitations and requires strict data ordering.

Changes:

  • Added on_before_game_save lua callback
  • Added on_game_save lua callback
  • Added on_before_game_load lua callback
  • Added on_game_load lua callback