AA-137: Support courseware celebrations

[BD-10] Remove unused course sock URL.

[BD-10] [DEPR-68][DEPR-84] Remove pattern library of learner_dashboard/programs.py

[BD-10] [DEPR-79] Remove pattern library of mobile/course-dates-fragment.html

[BD-10] [DEPR-70] Remove waffle flag edx_discussions.use_bootstrap. 

[BD-10] [DEPR-78][DEPR-82] Remove pattern library of latest-update-fragment.html and welcome-message-fragment.html

[BD-6] Fix python 3.8 compatibility

Mergeback PR from private to public.

Sustaining xsslint security fixes

[BD-10] [DEPR-83]

Removed confirm email after SSO

- Add a new CourseEnrollmentCelebration model, which ties a
  course enrollment to some booleans about progress celebrations
- Add serialization of the new model to the existing courseware_api
  app's existing course info view
- Add new API in courseware_api to update a celebration model

Use transifex client from PyPi since required change was merged recently.

MST-234

[PROD-1230] - syncing certificates on course update on credential side.

Revert "BOM-1703 : Ora2 Upgrade"

This reverts commit f3161468.

Revert "Add demographics prompt to edx.org theme"

AA-181: Updating Outline Tab API to include Course Blocks

AA-133 mfe dates banner

- add serializer mixin to expose date banner info
- add endpoint to reset deadlines for a sepcific course

[BD-5] [BB-2503] Add 'ENABLE_ORA_USERNAMES_ON_DATA_EXPORT' feature toggle

Add demographics prompt to edx.org theme

Change switch to waffle flag.