update error messages in enrollment API

ECOM-4763

Move cors_crsf to openedx/core

Clean up student/urls.py

Flaky course outline bok choy test.

This test has been very flaky on master, but the failure
is not reproducible. Trying a few things that might help.
TNL-5758

Fix textbook tests so a11y tests only run in a11y test phase

removing extra instance of MILESTONES_APP

Not able to reproduce flakiness.
TNL-5513

Updating logging for TNL-5697

Christina/javascript loader

New inline discussion home view TNL-4756

Stabilize textbook tests

Update translations (autogenerated message)

TNL-4756

for TNL-5697

Cdodge/restricted oauth2 applications

Allows ChoiceResponse problems to set correctness with python variables

determine choice correctness, as MultipleChoiceResponse problems already do.

Adds a unit test for this change, and for the existing MultipleChoiceResponse
computed correctness capability.

Update persistent grades asynchronously

ORA version update

Move dark_lang and lang_pref apps to openedx/core

Merge hotfix back to master.

Pull hotfix in to release branch.

For better user-facing performance, the SCORE_CHANGED signal is now handled by
enqueueing an async task to update the relevant stored grade, rather than
making the request wait until that operation finishes.

TNL-5738

Also reformat to 4 spaces per indent.

Revert "Cdodge/restricted oauth2 applications"

Fix for spurious 'cb() never called' errors.

Cdodge/restricted oauth2 applications

Also, help with an echo.

Fix flaky bokchoy test: test_automatic_cohort_help, test_manual_cohort_help