message: Add difficulty setting to CrimeExecution module
diff: #include "../UI/NotificationArea.h"
  #include "../Things/Structures/Structures.h"
  +#include "../Common.h"
  #include <vector>
  @@ -10,10 +11,13 @@ class CrimeExecution
  public:
  CrimeExecution(NotificationArea& notificationArea);
  + void difficulty(Difficulty difficulty) { mDifficulty = difficulty; }
  +
  void executeCrimes(const std::vector<Structure*>& structuresCommittingCrime);
  void executeStealingFood(FoodProduction& structure);
  private:
  + Difficulty mDifficulty{ Difficulty::Medium };
  NotificationArea& mNotificationArea;
  };
  