Concentric circles on the galaxy map for ships and colonies

**What do you want to see?**
The galaxy map currently shows a circle for each system based on who's there. Change this to two concentric circles - the inner one for colonies, the outer one for ships.

**How would it help players?**
Now you can see which systems are under threat and where your fleets are in enemy territory! The two don't look identical!

**Alternatives**
Semicircles instead of concentric circles? A big circle and a little circle in its orbit?

**Screenshots and mockups**
N/A

**Things to consider**
Could the little colony circles be too small on a big map?

**Related issues**
N/A