Use a non-constant cloud effective radius for radiation

[szy21]

Currently, we are assuming a globally constant effective radius for liquid and ice clouds in radiation here. We should change it to the values we get from microphysics.

[trontrytel]

That should actually be easy. We have those thanks to @crocicc :)

I'll get on it after we are done with dycore paper updates.

[szy21]

That's great, thanks!