Get students experiments, groups, and cohorts

common/lib/xmodule/xmodule/partitions/partitions_service.py

...n/lib/xmodule/xmodule/partitions/tests/test_partitions.py

common/lib/xmodule/xmodule/tests/test_split_test_module.py

lms/djangoapps/instructor_task/tasks_helper.py

lms/djangoapps/instructor_task/tests/test_integration.py

lms/djangoapps/instructor_task/tests/test_tasks_helper.py

lms/djangoapps/lms_xblock/runtime.py

openedx/core/djangoapps/course_groups/cohorts.py

openedx/core/djangoapps/course_groups/tests/test_cohorts.py

openedx/core/djangoapps/user_api/partition_schemes.py

.../core/djangoapps/user_api/tests/test_partition_schemes.py