Cleanup/chgres cube modules

[kgerheiser]

Making this a draft PR to start, but I ran the regression tests and all passed.

In this PR:

• Add the remaining code into modules (Put rest of chgres_cube code into modules #461), and this leads to a circular dependency between write_data and atomsphere.F90/surface.F90. I move out the target fields into their own module similar to how input_data.F90 contains all the _input_grid fields.

• Split input_data.F90 into 3 modules: atm_input_data.mo, sfc_input_data_mod, nst_input_data_mod, to make the files more managable. (Split input_data.F90 into atm_input_data, sfc_input_data, and nst_target_data #460)

• Remove find_package(w3emc) and find_package(gfsio) (some packages required in CMakeLists.txt which are no longer needed? #449)

Thoughts on this?

[GeorgeGayno-NOAA]

Making this a draft PR to start, but I ran the regression tests and all passed.

In this PR:

• Add the remaining code into modules (Put rest of chgres_cube code into modules #461), and this leads to a circular dependency between write_data and atomsphere.F90/surface.F90. I move out the target fields into their own module similar to how input_data.F90 contains all the _input_grid fields.
• Split input_data.F90 into 3 modules: atm_input_data.mo, sfc_input_data_mod, nst_input_data_mod, to make the files more managable. (Split input_data.F90 into atm_input_data, sfc_input_data, and nst_target_data #460)
• Remove find_package(w3emc) and find_package(gfsio) (some packages required in CMakeLists.txt which are no longer needed? #449)

As an FYI, I was planning to remove the unused packages under my own branch. If you want to do that here, then remove those libraries from all the build modules and update the README.md file. I like what you are doing, but you may be trying to do too many things under one PR.

Thoughts on this?

[kgerheiser]

Fair enough. It just kind of ended up that way as I was figuring out the code. I will split it up into 2 PRs. You can do the find_package thing.