Substation Mapfix Two

- Implemented suggestions (mainly by @Zuhayr, thanks!)
- Substation rooms now have some random stuff in them, so they don't look so empty. This varies by substation room. Arrivals gets generic emergency equipment as well as portable pump filling station, science gets firefighting gear, etc.)
- Rerouted some wiring to avoid putting wires under walls.
- Substation PSUs were changed to SMESs
- All SMESs onboard should be of /buildable/ subtype now. Including solars and substations