Added TC-Gen METplus use case for -genesis -edeck -shape options

[KathrynNewman]

Pull Request Testing

• Describe testing already performed for these changes:
  
  This is a use case for the tc-gen tool which demonstrates the deterministic and probabilistic capabilities. Automated tests show no runtime errors in Github Actions, data should be available on Mohawk, and documentation was added.

• Recommend testing for the reviewer(s) to perform, including the location of input datasets, and any additional instructions:
  
  Data for this use case are on available on seneca under: /d1/personal/knewman/tc-gen/data/model_applications/tc_and_extra_tc/TCGen_fcstGFS_obsBDECK_2021season.

• Do these changes include sufficient documentation updates, ensuring that no errors or warnings exist in the build of the documentation? [Yes]

• Do these changes include sufficient testing updates? [Yes]

• Will this PR result in changes to the test suite? [No]
  
  If yes, describe the new output and/or changes to the existing output:
  

• Please complete this pull request review by [3/3/2022].
  

Pull Request Checklist

See the METplus Workflow for details.

• Review the source issue metadata (required labels, projects, and milestone).
• Complete the PR definition above.
• Ensure the PR title matches the feature or bugfix branch name.
• Define the PR metadata, as permissions allow.
  Select: Reviewer(s) @georgemccabe @j-opatz @JohnHalleyGotway @halperin-erau
  Select: Organization level software support Project or Repository level development cycle Project
  Select: Milestone as the version that will include these changes
• After submitting the PR, select Linked issues with the original issue number.
• After the PR is approved, merge your changes. If permissions do not allow this, request that the reviewer do the merge.
• Close the linked issue and delete your feature or bugfix branch from GitHub.

[KathrynNewman]

New use case added as described in issue #1274

[georgemccabe]

Closing -- see #1492 for PR that will be merged.