NPC flee from being run over by vehicles

[SurFlurer]

Summary

Bugfixes "NPC flee from being run over by vehicles"

Purpose of change

This feature traces back to #120. However it's not working because of buggy code.

Describe the solution

The PR reuses the collision-preventing code for autonomous driving protocol, to determine whether the NPC will be run over by a vehicle. If true, make the NPC flee from the player.

Describe alternatives you've considered

1. Fine tune the flee behavior, e.g. running sideways away from the vehicle.
2. Extend the search range for dangerous vehicles.

Testing

1. Spawn a few bandits.
2. Spawn a car and drive toward them.
3. They do try to escape from the car ( though with poor results, because they usually can't move faster than 1 maptile per turn.)

Additional context