Updated CDSTest test data (Issue 20672):
The majority of these changes were made to provide data for the Learn About pages.

Changes:
- Updated Demo Subset, CHAVI 001, and CHAVI 008 to include visit tags
- Field adjustments for study properties:
  - Drop StudyType
  - Change label on Phase to "Study Type"
  - Add Stage
  - Add Title
  - Add Objectives
  - Add StudyPopulation
- Fill in Category for all datasets
- Add Target Type & Target Subtype for HIV-1 RT-PCR assay
Merge remote-tracking branch 'origin/develop' into develop