Update the gdas_init utility for the new NCO-specified 'model' directory

[GeorgeGayno-NOAA]

DESCRIPTION OF CHANGES:

Update the gdas_init utility for the new NCO-specified 'model' directory in COM
paths -> model_data is now just model.

TESTS CONDUCTED:

The gdas_init utility was tested on Hera. See the comments for details.

DEPENDENCIES:

N/A

DOCUMENTATION:

N/A

ISSUE:

Fixes #967.
Related to: NOAA-EMC/global-workflow#2686

[GeorgeGayno-NOAA]

Using the branch at 28164db, the gdas_init utility was tested on Hera. Coldstart files for CDUMP=gfs and CDUMP=gdas were created for a 2024/06/01/06z cycle. The coldstart files were stored in a directory named 'model' as specified by NCO:

ENKF files:

/scratch2/NCEPDEV/stmp1/George.Gayno/gdas.init/output/enkfgdas.20240601/06/mem001/model/atmos/input $ ls
gfs_ctrl.nc        gfs_data.tile2.nc  gfs_data.tile4.nc  gfs_data.tile6.nc  sfc_data.tile2.nc  sfc_data.tile4.nc  sfc_data.tile6.nc
gfs_data.tile1.nc  gfs_data.tile3.nc  gfs_data.tile5.nc  sfc_data.tile1.nc  sfc_data.tile3.nc  sfc_data.tile5.nc

GDAS files:

/scratch2/NCEPDEV/stmp1/George.Gayno/gdas.init/output/gdas.20240601/06/model/atmos/input $ ls
gfs_ctrl.nc        gfs_data.tile2.nc  gfs_data.tile4.nc  gfs_data.tile6.nc  sfc_data.tile2.nc  sfc_data.tile4.nc  sfc_data.tile6.nc
gfs_data.tile1.nc  gfs_data.tile3.nc  gfs_data.tile5.nc  sfc_data.tile1.nc  sfc_data.tile3.nc  sfc_data.tile5.nc

GFS files:

/scratch2/NCEPDEV/stmp1/George.Gayno/gdas.init/output/gfs.20240601/06/model/atmos/input $ ls
gfs_ctrl.nc        gfs_data.tile2.nc  gfs_data.tile4.nc  gfs_data.tile6.nc  sfc_data.tile2.nc  sfc_data.tile4.nc  sfc_data.tile6.nc
gfs_data.tile1.nc  gfs_data.tile3.nc  gfs_data.tile5.nc  sfc_data.tile1.nc  sfc_data.tile3.nc  sfc_data.tile5.nc

[KateFriedman-NOAA]

Looks good, thanks @GeorgeGayno-NOAA !

[GeorgeGayno-NOAA]

@KateFriedman-NOAA - merged!