When running with LILAC, do area corrections on fluxes

As @mvertens pointed out to me: If CTSM's internal areas disagree with the areas on the mesh, then we should be doing area corrections on the fluxes. Although she didn't say so, I assume we should be doing the same for the atmosphere.

In addition to adding this area correction code, we'll also need to extract areas from the mesh, related to this todo in the code:

https://github.com/ESCOMP/CTSM/blob/62b8d39a1a60964c87ca82e4849736c3bfd3f4ff/lilac/src/lilac_atmcap.F90#L256-L261