MPAS applications: add processing for lat–lon projection, add soil fields (TSOIL, SOILW)

[jaymes-kenyon]

The INITPOST_MPAS interface (adapted from INITPOST) does not currently process model output on a latitude–longitude projection (i.e., MAPTYPE = 0). This projection is used in GSL's modeling system for the Hurricane Forecast Improvement Project (HFIP–MPAS). UPP produces GRIB2 files for this model, but the grid lengths are decoded by wgrib2 as "0". For this reason, the GRIB2 files are not currently useable from HFIP–MPAS.

Additionally, soil temperature (TSOIL) and and soil moisture (SOILW) are missing from the GRIB2 output in both the HFIP–MPAS and RRFS–MPAS. It appears that the netCDF "ZS" array (depths of the soil layers) is not being created or read-in correctly.