Adding an on_radar_circuit_network_created event

[Galdoc]

tl;dr

When a circuit network is created that involves a Radar on a surface for the first time, a red and/or green network is created. I would like this to raise an event, and be able to access the circuit network ID.

Why

I'm working on an overhaul that involves linking together particular combinations of global circuit networks, and building the logic on events is much better than having to rummage through all of the entities. This is an event that would fire VERY infrequently throughout gameplay.

It's related to the topic here, which would be even better, but this is much narrower in scope.

[Galdoc]

I have been educated. It turns out that this is not quite how it works.

The way it works under the hood is that if you build a radar on a surface where there's already a radar connected to a circuit network ... they are then connected by invisible red/green wires, no matter the distance. You can see it by turning on 'see debug wires' in the F4 menu. It's amazing. Try it.