[z2203] Add possibility to toggle WaypointMovement WaitTimer

* Use this to allow SCRIPT_COMMAND_TERMINATE_SCRIPT to toggle the WaitTimer of a waypoint-moving creature
* Also fix a typo in recent commit, thx to Grz3s for pointing

(based on commit [12298] - 44bf5de)

(based on commit [s1837] - d82c010)