Change ATC map options section to VATSIM

[Velocity]

[StixAviation]

This is something that will remain the same unless we separate VATSIM ATC from IVAO if/when we implement it. ATC seems much more broad, and adding more tabs in the future will make the UI a bit cramped.

[Velocity]

I agree, perhaps name it "Networks" or "Online Networks". ATC in this case is wrong, it does include pilots as well

[StixAviation]

I see your point, and I agree. I'll discuss it with the rest of the developers and we'll get it settled.