Adds functionality to empty a transit pod or put mobs in one

Clicking on a transit station with an empty hand will cause you to attempt to empty the contents of the pod onto the floor, takes 4 seconds

Clicking on a transit station with a grab item in the aggressive state or above will cause you to attempt to stuff the grabbed mob into the pod, takes 6 seconds
EDIT1: Caused stuffing people in pods to stun them for 5 seconds to assist transport of captured persons

Fixes #1997, although the AI will require assistance from a crew member