Remove mongoengine constraint to upgrade package avoiding raising StopIteration since after python 3.7 is produces an error.

[BD-6] Order VideoBlock html metadata alphabeticallly to fix test.

override enrollment attributes for learners

ENT-2998

AA-44: Adding due dates into courseware

the new keyword async is causing errors when we run this with python 3.8.
https://docs.python.org/3/whatsnew/3.7.html

I tried in the first place, to change the definition of that value in the place where the context is defined, but it seems that it is taken from https://github.com/jazzband/django-pipeline,

This solves many problems for lms and cms tests that were making the jenkins workers get timeout.

That template have not seen changed since 2012, so I had to do additional changes in the templates in order to pass the xsslint checks:

mako-missing-default
mako-invalid-html-filter

I am not sure about the remove of the safe filter.

But I didn't found information about the 'safe' filter. It is probably that the now default 'h' filter is enough.

Due dates will only display for graded subsections.
If the assignment has already been completed, there will be a pill
to indicate that. If the assignment is past due, there will be a
pill. If it is upcoming, there are no pills

Python Requirements Update

As of Python 3.7, a backslash-character pair that is not a valid escape sequence now generates an error, earlier it was a deprecation warning.

AA-186: Updating Course Home Course Metadata API

PROD-1753

[BD-6] Fix test for python3.8

BOM-1750

Change validation code to use the value of the proctoring_provider mo…

Change validation code to use the value of the proctoring_provider model when making a comparison instead of the entire model. Otherwise, the condition 'current_provider != requested_provider' always resolves to True.

DeprecationWarning `callable is None` raised  since 3.5 throwing TypeError.
Fixed the assertion.

ARCHBOM-1304: add migration for flags using flag_undefined_default=True

In order to enable us to remove flag_undefined_default, this
updates flags according to alternatives documented in:
https://github.com/edx/edx-platform/blob/master/openedx/core/djangoapps/waffle_utils/docs/decisions/0001-refactor-waffle-flag-default.rst

These flags were updated with a migration:
- enable_checklists_quality
- REJECTED_EXAM_OVERRIDES_GRADE
- ENFORCE_FREEZE_GRADE_AFTER_COURSE_END
- WRITABLE_GRADEBOOK

ARCHBOM-1304

PROD-1565

* remove ENABLE_VIDEO_URL_REWRITE

The temporary waffle flag ENABLE_VIDEO_URL_REWRITE is no
longer needed, becaues the rollout is complete.
See https://openedx.atlassian.net/browse/PROD-62

ARCHBOM-1304

* fix quality

- update ADR to provide more alternatives for updating
the default value of a flag.
- add a `flag_` prefix to the flag metrics
- add module-level note about flag metrics
- add NewRelic query example and warning
- fix typo in toggle annotation

ARCHBOM-1302

AA-142 calendar sync ses

- set up util function to use Amazon SES for sending calendar
  sync emails.
- remove old sailthru code which we originally implemented for
  this functionality
- include ADR on our decision to use SES instead of Sailthru.

[REV-774] Show content type gating upsell when a limited access learner tries to access a timed exam

The temporary waffle flag ENABLE_VIDEO_URL_REWRITE is no
longer needed, becaues the rollout is complete.
See https://openedx.atlassian.net/browse/PROD-62

ARCHBOM-1304

Python Requirements Update

Fixing cgi.escape DeprecationWarning

AA-122 created framework for dates widget on course outline