Move ndrop_bam, nucleate_ice, and other microp_aero interstitials to atmos_phys

[jimmielin]

Tag name (The PR title should also include the tag name):
Originator(s): @jimmielin

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

• Moves nucleate_ice.F90 portable code to atmospheric_physics.
• Refactor and clean up ndrop_bam.F90 to be portable and move to atmos_phys.
• CCPPize interstitial schemes used in microp_aero: compute_subgrid_vertical_velocity, scale_subgrid_vertical_velocity, dust_default_radii

List all namelist files that were added or changed:

A       schemes/microp_aero/scale_subgrid_vertical_velocity_namelist.xml

List all files eliminated and why: N/A

List all files added and what they do:

A       schemes/microp_aero/nucleate_ice.F90
  - portable nucleate_ice code

A       schemes/microp_aero/ndrop_bam.F90
  - portable ndrop_bam code

A       schemes/microp_aero/compute_subgrid_vertical_velocity.F90
A       schemes/microp_aero/compute_subgrid_vertical_velocity.meta
A       schemes/microp_aero/scale_subgrid_vertical_velocity.F90
A       schemes/microp_aero/scale_subgrid_vertical_velocity.meta
A       schemes/microp_aero/dust_default_radii.F90
A       schemes/microp_aero/dust_default_radii.meta
  - CCPPized interstitial schemes used in microp_aero

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

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?
B4B in CAM
New chemistry/physics code (microp_aero)

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