Post-migration management command

On devops recommendation, now handling the potential for an 'inconsistency
window' via a management command instead of a hacky "re-run the data migration"
bash script.

New Relic transaction naming now ignores suffix most of the time.

Compare all refund dates in UTC

The only time it should include the suffix is when the handler is
explicilty "xmodule_handler", meaning it's an old-style handler
that routes everything. For example, Capa uses one handler for
all its AJAX requests, and only differentiates actions based on
suffix ("get", "problem_check", etc.).

What prompted this change is that LTIDescriptor defines a handler
"lti_2_0_result_rest_handler" which encodes user-specific
information into the suffix. This is a perfectly valid thing to
do, but it blows out the number of named transactions in our
metrics.

Applying a security patch from last week that has made its way through
the disclosure period already. FYI @robrap

mark test_can_reset_attempts as flakey as it sporadically fails

Fix dashboard page load error when cert_status is None

Show xseries upsell even if the course is not yet in session

ECOM-2780

Update translations (autogenerated message)

Add SampleCourseFactory and ToyCourseFactory

TNL-3478 Cohort Membership race condition fix

Marking flaky test

Increase the test output timeout and quiet the pylint output.

Move comments within the script block.

Add the html and css changes required for XSeries

common.test.acceptance.tests.video.test_video_module.YouTubeVideoTest.test_video_component_stores_speed_correctly_for_multiple_videos
is flaky, see for details.

By using the before_after library, we can force a race condition to reliably
occur in the CohortMembership.save() method. This unit test will do just that,
and ensure that our race-condition-handling code functions as it should.

Updating previously-existing unit tests to function with the new
CohortMembership model.

The code changes needed to get CohortMembership functioning properly.

The key of this change is twofold: first, CohortMemberships are unique
per-user, per-course. This is enforced at the database level. Secondly,
the updates are done using a select_for_update, which ensures atomicity.

These are the migrations needed for CohortMembership to function.
0005 establishes the table, 0006 will be used to move existing data
into the table as needed.

Per product guidance, we can just arbitrarily reassign problem users.
Implementing that decision, as well as the remainder of the data migration.

Also including a short script to re-run the 0006 migration after code changes
are live, to prevent a potential issue where the database become out-of-sync.

Timed Exams

Refund windows

SOL-1340: added vertical spacing around issued certificates section

Add configuration model for enrollment refunds.

Use order info from otto in refund window calculation

Delete dupe tests. Extend tests to include window tests

Move ecom client from lib to djangoapps in openedx

wrapped issued certificates section with p tags to add some vertical
spacing

changes after feedback from frances

indent code

MA-1189 - Discussion API: implemented GET comment children

MAYN-149 Survey Report CSV upload for Professional Education courses.

Pylint results should be piped.