Merge branch 'authoring' of https://github.com/edx/edx-ora2 into grady/ai-authoring

Conflicts:
	openassessment/xblock/defaults.py
	openassessment/xblock/static/css/openassessment.css
	openassessment/xblock/static/js/openassessment-studio.min.js
	openassessment/xblock/studio_mixin.py
	openassessment/xblock/test/data/invalid_update_xblock.json
	openassessment/xblock/test/data/update_xblock.json
	openassessment/xblock/test/test_studio.py