Nice interface for current solar power multiplier on a planet/space platform

[stolencheese]

Just got this report on my one mod, in which I was foolishly wrong on the internet.
https://mods.factorio.com/mod/ch-concen ... a26a0d5f3b

The core issue is that the thing that solar_power_multipler multiplies is now arbitrary rather than 1 in SA. Planets keep that multiplier as 1, which is unintuitive (and not mentioned on the docs, something that should be fixed even if this exact request is not accepted).

Took a look at how the solar calculator mod does it, and it seems overly convoluted and would require me to copy and test a mix of prototype and runtime apis. Which seems prone to error. Also did a quick search on the discord with similar discussion and conclusion, although couldn't find a request, so here we are.

My ideal solution is some nice surface.current_solar_power() or multiplier(), etc, that would also nicely change as space platforms move and the like, so I don't have to worry about the details.

Thanks!

[ahicks]

We'll also need this for Factorio Access.

I thought it was just going to be some linear combination of easy to find parameters or something, but if this request understands correctly sounds like that's not the case.