Adds mode creation endpoint to course_modes app and ability to bypass media device access prompt when proceeding through verification flow in a testing environment.

Added bokchoy tests and assets (csv files) for CSV auto reg and enrollment.
Set the env flag "ALLOW_AUTOMATED_SIGNUPS": true in bok_choy.env.json

Resolved quality issues.

resolved cherry pick conflicts

Improved bokchoy tests as per code review suggestions.

added the BDD in the docstrings for all the test scenarios

changed the bok choy test string

Improved bokchoy tests as per further code review suggestions.

Made a MembershipPageAutoEnrollSection a separate PageObject.

Including:

* Change path for mongo_metadata_inheritance to use unique temp dir
* Update SASS_CACHE_PATH with thread-safe temp dir
* Remove hard coded directory reference for grades download tests
* Remove hard coded directory reference for direct mongo test

Update db cache