* import task decorator from celery APP instance instead of celery package in CMS
* replaced task decorator with shared_task in cms and common
* Fixed import of shared_task
* Fixed import
When rolling out #25477, we dropped hundreds of email activation
tasks due to the renaming of student.send_activation_email
to common.djangoapps.student.send_activation_email,
and lost more when we rolled that PR back.
This happens because of blue/green deployment:
old workers are still online for a while after deploying,
so there is a period of time when the task names are mismatched.
To prevent this from happening again, this will make
it so the import changes don't change the names of
any of the Celery tasks.
* Generate common/djangoapps import shims for LMS
* Generate common/djangoapps import shims for Studio
* Stop appending project root to sys.path
* Stop appending common/djangoapps to sys.path
* Import from common.djangoapps.course_action_state instead of course_action_state
* Import from common.djangoapps.course_modes instead of course_modes
* Import from common.djangoapps.database_fixups instead of database_fixups
* Import from common.djangoapps.edxmako instead of edxmako
* Import from common.djangoapps.entitlements instead of entitlements
* Import from common.djangoapps.pipline_mako instead of pipeline_mako
* Import from common.djangoapps.static_replace instead of static_replace
* Import from common.djangoapps.student instead of student
* Import from common.djangoapps.terrain instead of terrain
* Import from common.djangoapps.third_party_auth instead of third_party_auth
* Import from common.djangoapps.track instead of track
* Import from common.djangoapps.util instead of util
* Import from common.djangoapps.xblock_django instead of xblock_django
* Add empty common/djangoapps/__init__.py to fix pytest collection
* Fix pylint formatting violations
* Exclude import_shims/ directory tree from linting
