[2.1] The new radar circuit channels could use some UI tweaks

[gridstop]

The new radar circuit networks are awesome but a couple simple UI tweaks would really help.

1) If a universe channel is selected, please show the icon over the radar when alt machine display is active, so you can see at a glance which network a radar is assigned to without having to click it and open the UI.
2) Also consider showing the universe channel in the tooltip display alongside the sector scan progress, and perhaps showing 'Surface' text when it's set to surface.
3) When the radar is connected to either type of network, the tooltip should probably show the circuit network ID# and current contents like combinators and power poles do.

#1 here is probably the most significant but yet simplest change, too. 2&3 are more nice to have.