AcceptsPlugs + Plug

Added TS’s GDI Power Turbine.
Currently this doesn't support selling (or selecting, etc.) plugs independently.

Possibly fixes #3211 (in one of two ways).

I should note there is an example ingame with TS but it does not work due to cell layout, I assume.
If you test this in RA/TD/D2k you will see that it works as expected.

This responds oddly with plugs that are not 1x1 due to our numerous topleft assumptions (which is not too surprising).