Drones releasing from ssu

Added the ability for drones to get out of suit storage units with the unit controls, fixing Issue #4904 . They were able to do this before by typing resist, but this adds a visual option.
This is my first pull request, so please tell me if I'm doing something / anything wrong!
Probably best to call CanUseTopic() in the place where you enter the SSU, since they shouldn't be able to crawl into SSUs into the first place tbh.