[develop] Split EnsembleStat tasks into GenEnsProd and EnsembleStat

[gsketefian]

DESCRIPTION OF CHANGES:

IMPORTANT: This PR builds on PR #683. Thus, that one has to be merged first. Currently, the changes shown in this PR also include the ones from PR #683. Once #683 is merged, the number of files changed will be far fewer (maybe around 35, all except 2 or 3 of which are the METplus conf files).

The latest versions of MET/METplus have introduced a new tool named GenEnsProd that performs many of the ensemble-related calculations that EnsembleStat used to do. Although EnsembleStat can still perform these calculations, that will change in future versions of MET/METplus. Thus, this PR creates new vx tasks that call GenEnsProd to perform the necessary calculations, removing them from the EnsembleStat tasks. Details:

1. Add new METplus config files for GenEnsProd.
2. Modify the EnsembleStat config files so that EnsembleStat no longer calculates the ensemble statistics that are now the purview of GenEnsProd.
3. Add sections to config_defaults.yaml for the new GenEnsProd tasks.
4. Add tasks to the ROCOTO XML to run GenEnsProd. Note that these are identical to the existing EnsembleStat tasks (they call the same j-job, define the same environment variables, etc) except for a change of task name and resource names (number of nodes, walltime, etc). Thus, they are very "loopable".
5. Modify the ex-scripts for the ensemble mean and probabilistic tasks so that they look for forecast input from the output of the GenEnsProd tasks, not the output of the EnsembleStat tasks.
6. Clean up the remaining METplus config files so that they are as similar as possible (for possible consolidation later on).

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

TESTS CONDUCTED:

• hera.intel
• orion.intel
• cheyenne.intel
• cheyenne.gnu
• gaea.intel
• jet.intel
• wcoss2.intel
• NOAA Cloud (indicate which platform)
• Jenkins
• fundamental test suite
• comprehensive tests (specify which if a subset was used)

I ran the following fundamental suite of tests on Hera with intel, and all passed:

MET_verification
MET_verification_only_vx
community_ensemble_2mems
grid_RRFS_CONUS_25km_ics_FV3GFS_lbcs_FV3GFS_suite_GFS_2017_gfdlmp
grid_RRFS_CONUS_25km_ics_FV3GFS_lbcs_FV3GFS_suite_GFS_2017_gfdlmp_regional_plot
grid_RRFS_CONUS_25km_ics_FV3GFS_lbcs_FV3GFS_suite_GFS_v15p2
grid_RRFS_CONUS_25km_ics_FV3GFS_lbcs_FV3GFS_suite_GFS_v16
grid_RRFS_CONUS_25km_ics_FV3GFS_lbcs_RAP_suite_HRRR
grid_RRFS_CONUS_25km_ics_GSMGFS_lbcs_GSMGFS_suite_GFS_v15p2
grid_RRFS_CONUScompact_25km_ics_HRRR_lbcs_RAP_suite_HRRR
grid_RRFS_CONUScompact_25km_ics_HRRR_lbcs_RAP_suite_RRFS_v1beta
grid_RRFS_CONUS_25km_ics_FV3GFS_lbcs_FV3GFS_suite_GFS_2017_gfdlmp_regional_plot
MET_ensemble_verification
MET_ensemble_verification_only_vx
community_ensemble_2mems_stoch
pregen_grid_orog_sfc_climo

In addition, I ran the MET_ensemble_verification test in NCO mode, and that also passed.

DEPENDENCIES:

This PR builds on PR #683. Thus, that has to be merged first.

DOCUMENTATION:

Documentation is needed but will be added once the whole set of vx PRs has been merged (see Issue #630).

CHECKLIST

• My code follows the style guidelines in the Contributor's Guide
• I have performed a self-review of my own code using the Code Reviewer's Guide
• I have commented my code, particularly in hard-to-understand areas
• My changes need updates to the documentation. I have made corresponding changes to the documentation
• My changes do not require updates to the documentation (explain).
• My changes generate no new warnings
• New and existing tests pass with my changes
• Any dependent changes have been merged and published