logistics network should show 'charging' robots

[AartBluestoke]

What:
1. Logistics network should show the count of robots seeking power,
2. any roboport with more than 10x charging platforms worth of robots queued in a circle around it should raise a warning.
3. new infinite research, roboport charging rate.

Why:
At the moment logistics robots have 2 status : idle, and working.
Logistics robots actually have a third status "seeking power". Robots in this state show as 'working' but are not contributing to any deliveries.

When logistics networks unexpectedly show as 100% in use, it is often because of insufficient localised power charging, resulting in a large buildup of robots awaiting power at some random roboport which is maximum distance from another and experiencing lots of traffic.

It is hard to find these places in a large factory (solved by 2), or even notice that of your 4k robots in use 3k of the are perpetually 'seeking charge'. (solved by 1)

Long term, the only way to solve this is by having a high density of roboports (way more than implied by their connection distance) in any area which has high traffic. In extreme circumstances you regulary see people painting blocks of roboports between a train station and the adjacent factory, just to get the 'bots charged.
This last issue would be solved by either higher charging rates, or lower energy usage. I picked the former for proposal 3, as making robots 'free' long term in a megafactory is probably not what the devs would intend.