Switch to using Pathways instead of CreditPathways.

common/djangoapps/terrain/stubs/catalog.py

common/test/acceptance/fixtures/catalog.py

common/test/acceptance/tests/lms/test_programs.py

lms/djangoapps/learner_dashboard/programs.py

lms/djangoapps/learner_dashboard/tests/test_programs.py

...templates/learner_dashboard/program_details_fragment.html

openedx/core/djangoapps/catalog/cache.py

.../djangoapps/catalog/management/commands/cache_programs.py

.../catalog/management/commands/tests/test_cache_programs.py

openedx/core/djangoapps/catalog/tests/factories.py

openedx/core/djangoapps/catalog/tests/test_utils.py

openedx/core/djangoapps/catalog/utils.py