Defaulting to a plaintext response makes no sense for an endpoint that is intended to be used by machines for testing. The endpoint now returns JSON only unless a redirect action is triggered.
The read_cached_programs switch was used to control the release of changes for reading programs exclusively from the cache. With those changes stable, the switch is no longer necessary.
LEARNER-382
This commit contains back end changes necessary to load programs from the catalog in all contexts. The existing program munging utility is applied as late as possible to avoid conflating this work with changes to the front end; those will be made separately.
ECOM-4422
Catalog-based MicroMasters need to be displayed in the LMS. However, the LMS currently retrieves all program data from the soon-to-be-retired programs service. Consuming program data exclusively from the catalog service is out of the question right now; it's too complex to confidently pull off in a week. This is a functional middle ground introduced by ECOM-5460. Cleaning up this debt is tracked by ECOM-4418.
