Improve the capture UI

Right now I see two problems with our current system:
- There is no range range-ring for the capture order, which means it is difficult to gage whether your ACU/engineer needs to walk before carrying out the capture order.
- Not really a UI problem, but capturing low buildtime units with a Tech 3 ACU is near instant. For instance, a Tech 1 PD takes bit over a second to capture, which is very hard to counter due to the 500ms delay the game has (self-destucting the unit is the counter to capturing).