Refactor badging, move into its own app.

lms/djangoapps/badges/__init__.py

lms/djangoapps/badges/admin.py

lms/djangoapps/badges/backends/__init__.py

lms/djangoapps/badges/backends/badgr.py

lms/djangoapps/badges/backends/base.py

lms/djangoapps/badges/backends/tests/__init__.py

lms/djangoapps/badges/backends/tests/test_badgr_backend.py

lms/djangoapps/badges/events/__init__.py

lms/djangoapps/badges/events/course_complete.py

lms/djangoapps/badges/events/tests/__init__.py

lms/djangoapps/badges/events/tests/test_course_complete.py

lms/djangoapps/badges/migrations/0001_initial.py

...goapps/badges/migrations/0002_data__migrate_assertions.py

lms/djangoapps/badges/migrations/__init__.py

lms/djangoapps/badges/models.py

lms/djangoapps/badges/tests/__init__.py

lms/djangoapps/badges/tests/factories.py

lms/djangoapps/badges/tests/test_models.py

lms/djangoapps/badges/utils.py

lms/djangoapps/certificates/admin.py