Refactor rad_constituents and abstract aerosol interface to share with CAM-SIMA

[jimmielin]

Issue Type

Infrastructure Update

Issue Description

Clean up / split rad_constituents into gases-aerosols and make portable to the same modules can be used in CAM-SIMA with reasonable changes (ideally most modules as-is)

Will be a bit-for-bit update

Will this change answers?

No

Will you be implementing this yourself?

Yes