Fism: Add ability to generate NEUVAC irradiances

[DanBrandt]

Description

Added neuvac.py within srcPython; generates a .txt file for irradiances from the NEUVAC model, in the same manner as fism.py.

Addresses # (issue)

Addresses the inability to use the NEUVAC model directly to generate irradiances, and supply them to Aether.

Type of change

• New feature (non-breaking change that adds functionality)
• This change requires a documentation update

How Has This Been Tested?

Change HAS NOT been tested.

Test configuration

N/A.

Checklist:

• [N/A] Make sure you are merging into the develop (not master) branch
• 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 made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules
• [N/A] Add a note to CHANGELOG.md, summarizing the changes