Remove remaining calls to routines in marine_da_utils.py

[DavidNew-NOAA]

Description

This PR removes calls to legacy routines in ush/python/pygfs/utils/marine_da_utils.py. Most of these calls were removed in previous PRs, and this one cleans up the remainder.

The code in get_mom6_levels() was moved into the Analysis class constructor and , so the number of mom6 levels becomes part of task_config, available for all marine tasks.

prep_input_yaml() is replaced by simply creating two .nml.j2 templates in GDASApp (rather than one) and invoking the new parse_j2tmpl from wxflow.

gen_bkg_list() was only called once in ush/python/pygfs/task/marine_analysis.py, so I moved its code into the constructor for the MarineAnalysis task.

test_hist_date() was only called in ush/python/pygfs/task/marine_analysis.py, so I made it a static method of the MarineAnalysis task.

run() is moved into the Analysis class.

Resolves #4355

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 (e.g. value changes to existing outputs, new files stored in COM, files removed from COM, filename changes, additions/subtractions to archives)? NO (If YES, please indicate to which system(s))
  • GFS
  • GEFS
  • SFS
  • GCAFS
• 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? YES (If YES, please add a link to any PRs that are pending.)
  • EMC verif-global
  • GDAS GDASApp companion to GW PR #4356 GDASApp#2014
  • GFS-utils
  • GSI
  • GSI-monitor
  • GSI-utils
  • UFS-utils
  • UFS-weather-model
  • wxflow

How has this been tested?

Clone, build, and CI on Hera

Checklist

• Any dependent changes have been merged and published
• 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
• I have documented my code, including function, input, and output descriptions
• 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
• Any new scripts have been added to the .github/CODEOWNERS file with owners
• I have made corresponding changes to the system documentation if necessary

[DavidNew-NOAA]

@aerorahul @DavidHuber-NOAA This PR is ready for review

[TravisElless-NOAA]

Things look alright to me. Approve pending testing. Will launch CI on Ursa

[aerorahul]

looks good. thanks. Just one suggestion to pop out the relevant error information in the traceback

[TravisElless-NOAA]

CI Passed. Merging

[DavidNew-NOAA]

Thanks @TravisElless-NOAA