Make metp jobs run in parallel

[DavidHuber-NOAA]

Description

This adds the capability to run the metplus jobs in parallel by applying a bugfix to the J-Job.

Type of change

• Bug fix (fixes something broken)
• New feature (adds functionality)
• Maintenance (code refactor, clean-up, new CI test, etc.)

Change characteristics

• Is this change expected to change outputs NO
• Is this a breaking change (a change in existing functionality)? NO
• Does this change require a documentation update? NO
• Does this change require an update to any of the following submodules? NO

How has this been tested?

Will test CI on WCOSS2

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• My changes generate no new warnings
• New and existing tests pass with my changes
• This change is covered by an existing CI test or a new one has been added

[DavidHuber-NOAA]

Running tests on Dogwood.

[DavidHuber-NOAA]

All tests passed on WCOSS2 and all metp* jobs ran on the first call. Statistics were also generated for most cases. It is worth noting that statistics were not generated for the C48_S2SW_extended, C96C48_hybatmsnowDA, and C96C48_hybatmsoilDA cases. There is a bug in verif-global that currently causes one-cycle (non-00Z) statistics generation. This is being fixed in NOAA-EMC/EMC_verif-global#200 and #4455 (along with other upgrades/fixes). This PR only addresses the capability of running metp jobs in parallel.

[DavidHuber-NOAA]

This PR is now ready for review.

[CatherineThomas-NOAA]

Code changes look good to me.

I poked around in your test directories and things look as expected: I see your XML file now has mode="parallel", it looks like all 3 metp jobs started around the same time, and the $DATA directories are cleaned appropriately. Thanks @DavidHuber-NOAA!