UPP failed when GF scheme applied #51

Issue:
Attempted to use MPAS App with Grell-Freitas enabled. The UPP crashed with errors related to the CRTM inputs (which drive synthetic satellite imagery). Provided a different UPP control file and UPP executable but we still encountered crashes, likely because the MPAS App yaml controlling the experiment was still pointing to the default control file.

Clark's proposed solution:
This should be specified in the experiment-specific yaml for MPAS App. The nested hierarchy is:

post:
upp:
control_file: "{{ user.mpas_app }}/parm/upp/postxconfig-NT.txt"

...which assumes that the postxconfig-NT.txt has been placed in the base mpas_app/parm/upp/ directory.

The conus.jet.yaml file that provides defaults for the MPAS App is what is driving UPP to use the postxconfig-NT-rrfs_mpas.txt file:

control_file: "{{ user.mpas_app }}/parm/upp/postxconfig-NT-rrfs_mpas.txt"

And to add to this, there's also another entry (files_to_copy) that may need changed in the experiment-specific yaml:

post:
upp:
files_to_copy:
postxconfig-NT.txt: "{{ user.mpas_app }}/parm/upp/postxconfig-NT.txt"