Decrease Video Player Init Wait Timeout
Refactor LMS Video Tests
Fix property call issue
Catch InvalidKeyError in UserTagsEventContextMiddleware.

LMS-11189
Catch InvalidKeyError in static_tab view.

LMS-11189
Replace `check_for_get_code` with `assert_request_status_code`

More flexible, uses the word "assert", method instead of function
make expanding explanation accessible

LMS-11161
Toggle aria-expanded attribute
BLD-1125: Validation of content experiments after managing a group.
Added styling.
Added Jasmine tests.
REVERT THIS BEFORE MERGE.