Able to enable full staff grading from studio, save without errors, and view
the staff grading step as expected from LMS.

Includes:
    -template additions, staff grading disabled by default
    -fetching real staff requirements
    -javascript to hook into the python backend
    -changing some default assumptions about assessment types
    -modifications to validation
    -small bugfix for scroll behaviorwith validation alert.
    -updates to existing unit tests
    -additional validation, serialization, and javascript tests
    -fix for staff requirements bug (no more duble-unpacking)
    -updates the bundled studio js file
    -moving StaffWorkflow initilization to api's on_init() method
    -acceptance tests (lms)
    -addition of "Staff Assessment Section" to test course for bokchoy tests
    -renaming `requirements` to `<type>_requirements` in assessment apis