Pygmet prep

[richardarsenault]

Pull Request Checklist:

• This PR addresses an already opened issue (for bug fixes / features)
  • This PR fixes #xyz
• (If applicable) Documentation has been added / updated (for bug fixes / features).
  • If changes affect the GIS, Raven Modelling, Extremes.jl or Use Case Example notebooks, they have been re-run (ReadTheDocs will not update these).
  • If text has changed, make initialize-translations / make-translations.bat has been run and translations have been updated.
• (If applicable) Tests have been added.
• CHANGELOG.rst has been updated (with summary of main changes).
  • Link to issue (:issue:number) and pull request (:pull:number) has been added.

What kind of change does this PR introduce?

• This PR integrates the functions needed to prepare input and configuration files for running PyGMET, which generates ensemble meteorological grids based on an input grid, representing uncertainty.

Does this PR introduce a breaking change?

No

Other information: