Merge pull request #11198 from edx/block-cache/collect-phase

lms/djangoapps/course_api/blocks/api.py

lms/djangoapps/course_api/blocks/tests/helpers.py

lms/djangoapps/course_api/blocks/tests/test_api.py

lms/djangoapps/course_api/blocks/tests/test_forms.py

lms/djangoapps/course_api/blocks/tests/test_serializers.py

lms/djangoapps/course_api/blocks/tests/test_views.py

...djangoapps/course_api/blocks/transformers/block_counts.py

lms/djangoapps/course_api/blocks/transformers/block_depth.py

lms/djangoapps/course_api/blocks/transformers/blocks_api.py

lms/djangoapps/course_api/blocks/transformers/navigation.py

...angoapps/course_api/blocks/transformers/proctored_exam.py

...djangoapps/course_api/blocks/transformers/student_view.py

...course_api/blocks/transformers/tests/test_block_counts.py

.../course_api/blocks/transformers/tests/test_block_depth.py

...s/course_api/blocks/transformers/tests/test_navigation.py

...urse_api/blocks/transformers/tests/test_proctored_exam.py

...course_api/blocks/transformers/tests/test_student_view.py

lms/djangoapps/course_blocks/__init__.py

lms/djangoapps/course_blocks/api.py

lms/djangoapps/course_blocks/management/__init__.py