Merge pull request #20201 from edx/mroytman/EDUCATOR-4159-masters-only-logged-in

common/djangoapps/course_modes/models.py

common/djangoapps/course_modes/tests/test_models.py

lms/djangoapps/courseware/tests/test_views.py

lms/djangoapps/courseware/views/views.py

openedx/features/course_experience/tests/views/helpers.py

...eatures/course_experience/tests/views/test_course_home.py

.../features/course_experience/views/course_home_messages.py