Roboport: statistics for individual roboports

[roothorick]

Simple and straightforward (I hope). Add two new outputs for the "Read robot statistics" mode: "Logistic bots parked here" and "Construction bots parked here", indicating the number of bots currently inside only the roboports attached to that circuit network..

After all, isn't optimizing efficiency the player's job? Seems like balancing robots in the logistic network would fall under that.

[Optera]

Inventory sensor will read bots and repair packs inside a roboport.
It certainly would improve performance if roboports would directly report those statistics.

I wish we could somehow filter and lock slots, so bots would spread better across the network, but that was a different suggestion.