Revert "Merge pull request #13614 from edx/efischer/revert_grades"

common/lib/xmodule/xmodule/graders.py

common/lib/xmodule/xmodule/tests/test_graders.py

common/test/data/blocks/capa.xml

common/test/data/blocks/coderesponse.xml

common/test/data/blocks/library_content.xml

common/test/data/blocks/lti.xml

common/test/data/blocks/openassessment.xml

lms/djangoapps/gating/tests/test_api.py

lms/djangoapps/grades/models.py

lms/djangoapps/grades/new/course_grade.py

lms/djangoapps/grades/new/subsection_grade.py

lms/djangoapps/grades/scores.py

lms/djangoapps/grades/tests/test_grades.py

lms/djangoapps/grades/tests/test_models.py

lms/djangoapps/grades/tests/test_new.py

lms/djangoapps/grades/tests/test_scores.py

lms/djangoapps/grades/tests/utils.py

lms/djangoapps/instructor/enrollment.py

lms/djangoapps/instructor/tests/test_enrollment.py

lms/djangoapps/instructor_task/tasks_helper.py