EDUCATOR-1400

Add a new waffle switch that allows us to assume zero grades for
learners who have no entry previously recorded, and another to
disable persisting grades for unengaged learners.

TNL-6691

for TNL-5045

For TNL-5993

* Centralize creation of quick request objects.
* Isolate caches to individual tests to prevent test ordering
  dependencies.

TNL-5811

Makes use of the new SUBSECTION_SCORE_CHANGED signal to trigger a task that
updates persisted course grade values. We've also renamed SCORE_CHANGED to
PROBLEM_SCORE_CHANGED to head off any issues with unclear signal names.

TNL-5740

TNL-5046

This reverts commit 9aa35cd8.

fixes signal handling for delete student state

This reverts commit 0ea8e1b9, reversing
changes made to e3db08f1.

Potential Grades revert PR

This reverts commit e3db08f1, reversing
changes made to 51c2444d.

clear_student_state(), a method defined by ORA, requires information
about the user making the request. Since this xblock is not bound,
we must provide that information explicitly.

Please note that this is a squshed commit and the work of:
Symbolist, macdiesel, nedbat, doctoryes, muzaffaryousaf and muhammad-ammar

This change allows graded assignments to be added to a campus LMS
regardless of the granularity at which the problem sits. Previously
a grade could only be returned if the usage ID for the problem itself
was specified in the LTI launch.

The code assumes that courses taking advantage of this functionality
are arranged in a hiearchy (with sections being parents to verticals,
and verticals being parents to problems). When a grading event occurs
it traverses the parent hiearchy to identify any previous graded LTI
launches for which the new scoring event should generate a grade
update. It then calculates and sends scores to each of those outcome
services.

Since grade calculation is an expensive operation, the code optimizes
the case where a problem has been added only once as a leaf unit. In
that case it is able to behave as before, just taking the grade from
the signal without having to calculate grades for the whole course.

Also added reset_test_case() and @modifies_courseware to SharedModuleStoreTestCase.

Revert "More verbose test builds in Jenkins, for debugging."

This reverts commit 58cade4cc4288335026649470a48b7bbca969ee8.

	modified:   lms/djangoapps/instructor/tests/test_enrollment.py

The existing pattern of using `override_settings(MODULESTORE=...)` prevented
us from having more than one layer of subclassing in modulestore tests.

In a structure like:

    @override_settings(MODULESTORE=store_a)
    class BaseTestCase(ModuleStoreTestCase):
        def setUp(self):
            # use store

    @override_settings(MODULESTORE=store_b)
    class ChildTestCase(BaseTestCase):
        def setUp(self):
            # use store

In this case, the store actions performed in `BaseTestCase` on behalf of
`ChildTestCase` would still use `store_a`, even though the `ChildTestCase`
had specified to use `store_b`. This is because the `override_settings`
decorator would be the innermost wrapper around the `BaseTestCase.setUp` method,
no matter what `ChildTestCase` does.

To remedy this, we move the call to `override_settings` into the
`ModuleStoreTestCase.setUp` method, and use a cleanup to remove the override.
Subclasses can just defined the `MODULESTORE` class attribute to specify which
modulestore to use _for the entire `setUp` chain_.

[PLAT-419]

Enrollment, unenrollment and beta role emails should be rendered in the
student's language, and not the instructor's language.

Move modulestore config for tests to an importable location
Disable pylnt warning for lms imports in common tests
Refactor all testcases that loaded all xml courses
TE-610
TE-489

TE-489