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!
Also, we don't usually report bugs on the changelog, it clogs things up and makes it harder to see the actual new stuff.