Add 3DVar aerosol test

[CoryMartin-NOAA]

• [x] Need workflow branch merged in
• [x] modify C48 ICs to have aerosols in them
• [ ] create aerosol expdir
• [ ] create ctest

[CoryMartin-NOAA]

Picking back up on this because of https://github.com/NOAA-EMC/global-workflow/issues/1821

[CoryMartin-NOAA]

Work is in https://github.com/NOAA-EMC/GDASApp/tree/feature/aero_3dvar_test, things are progressing but need to get sample observations reprocessed.