part of atmos_phys0_31_000: Use CCPP-framework provided constituent lookup instead of homegrown method

[nusbaume]

Tag name (The PR title should also include the tag name):
Originator(s): nusbaume (with actual code mods coming from Claude Opus-5.5)

Description (include issue title and the keyword ['closes', 'fixes', 'resolves'] and issue number):

This PR replaces the use of the locally-provided ccpp_const_get_idx with the CCPP-framework provided ccpp_constituent_index subroutine, and removes the no-longer-needed ccpp_const_utils.F90. Beyond just code clean-up, this switch provides two major advantages:

1. It increase physics scheme portability, as all CCPP host models should have access to ccpp_constituent_index
2. It improves performance by replacing a linear search method with a hash table, thus improving performance from O(n) to O(1).

Fixes #215
Addresses #137

List all namelist files that were added or changed: N/A

List all files eliminated and why:

D       to_be_ccppized/ccpp_const_utils.F90
 - The module is no longer needed/used.

List all files added and what they do:

A       test/musica/musica_test_constituents.F90
  - Helper routine used to run the MUSICA test.

List all existing files that have been modified, and describe the changes:
(Helpful git command: git diff --name-status main...<your_branch_name>)

M       schemes/bretherton_park/bretherton_park_diff.F90
M       schemes/bretherton_park/bretherton_park_diff.meta
M       schemes/hack_shallow/hack_convect_shallow.F90
M       schemes/holtslag_boville/holtslag_boville_diff_interstitials.F90
M       schemes/holtslag_boville/holtslag_boville_diff_interstitials.meta
M       schemes/musica/musica_ccpp.F90
M       schemes/musica/util/musica_ccpp_species.F90
M       schemes/sima_diagnostics/diffusion_solver_diagnostics.F90
M       schemes/sima_diagnostics/diffusion_solver_diagnostics.meta
M       schemes/sima_diagnostics/gravity_wave_drag_common_diagnostics.F90
M       schemes/sima_diagnostics/gravity_wave_drag_common_diagnostics.meta
M       schemes/vertical_diffusion/vertical_diffusion_interstitials.F90
M       schemes/vertical_diffusion/vertical_diffusion_interstitials.meta
 - Update schemes to use 'ccpp_constituent_index'

M       test/musica/CMakeLists.txt
M       test/musica/aerosol/CMakeLists.txt
M       test/musica/aerosol_stub/CMakeLists.txt
A       test/musica/musica_test_constituents.F90
M       test/musica/test_musica_api.F90
M       test/musica/test_musica_species.F90
M       test/musica/tuvx/CMakeLists.txt
M       test/musica/tuvx/test_tuvx_gas_species.F90
M       test/musica/util/CMakeLists.txt
 - Update MUSICA test to use 'ccpp_constituent_index'

List all automated tests that failed, as well as an explanation for why they weren't fixed:

Is this an answer-changing PR? If so, is it a new physics package, algorithm change, tuning change, etc?

No, this PR will not change answers.

If yes to the above question, describe how this code was validated with the new/modified features:

[jimmielin]

Thanks @nusbaume! Just a few notes that didn't fit in particular locations:

• This changes several schemes (HB, UW, ...) to remove const_props, so a CAM update is needed
• If a CAM update is made, the lookup might need to be updated to be case-insensitive, and also return errcode=0 with int_unassigned instead of errcode=1 when not found (this might crash a good amount of CCPP schemes)

[nusbaume]

Great catch @jimmielin! I've made ESCOMP/CAM#1711 to implement the needed CAM-side changes.

[peverwhee]

looks great to me!

[jimmielin]

merged as part of #433