Add an option to track/highlight individual signals on GPS units and suit sensors

[Sheeplets]

As written. It's pretty hard to keep track of things or people you're trying to move towards as a miner, EMT, engineer, etc. This includes yourself and your own position, of course.

I wish we could just be able to hit a "TRACK" button on the far right of the window which brings the tracked signatures you need to the top and highlights them. Sort of like how GPS units work now, except without needing to de-list everything else in the process.