What's Changed
- Add `staffgrader` app
- Add `staff_grader_mixin` which adds several xblock handlers that act as a json ora api for listing submissions and getting assessment lock and submission information to enable the frontend.
- Add `SubmissionGradingLock` model to represent a "locked" submission so that only one grader may grade a submission at a given time.
- Add `create_oa_submissions_from_file` management command for bulk creation of test users submissions assessments and locks
- Add ESG linking form instructor dashboard
- Add file size info to file descriptors
- Remove debug toolbar from ORA
**Full Changelog**: https://github.com/openedx/edx-ora2/compare/3.7.8...3.8.0