Consolidate NEXCLOUD test data repository lists

[mindyls]

Requested Update

Description

• Consolidate test dataset lists

Background and Motivation

• Currently list of test datasets available on NEXCLOUD is specified in 2 locations:
  • https://github.com/NRLMMD-GEOIPS/geoips/blob/main/setup/check_system_requirements.sh#L49
  • https://github.com/NRLMMD-GEOIPS/geoips/blob/main/geoips/commandline/ancillary_info/test_data.py
• Consolidate these lists in a single location.
• NOTE: incoming github.nrlmry update will remove dupliate test_data_scat repos - we should only have a single test data repository per dataset - older test data repositories are only retained for reference.

Alternative Solutions

• [ OPTIONAL: If appropriate, list alternative fixes that could be considered]

Environment

• geoips >= 1.13.0

Code to demonstrate issue

• [ IF APPROPRIATE: Can include steps here to identify/demonstrate bug fix or desired feature ]

Checklist for Completion

• [ ] <!--- Include a list of steps that must be complete in order to close this Issue --->