[FC-0099] refactor: manage enforcer state and casbin models only when app is ready

[mariajgrimaldi]

Description

This PR fixes an issue with including the library in non-testing environments since the Casbin adapter was trying to access the database when the apps were not fully loaded, raising errors like:

 > [production 19/37] RUN ./manage.py lms --settings=tutor.i18n pull_plugin_translations --verbose --repository='openedx/openedx-translations' --revision='release/teak.2':
4.409 Traceback (most recent call last):
4.409   File "/openedx/edx-platform/./manage.py", line 99, in <module>
4.409     execute_from_command_line([sys.argv[0]] + django_args)
4.409   File "/openedx/venv/lib/python3.11/site-packages/django/core/management/__init__.py", line 442, in execute_from_command_line
4.409     utility.execute()
4.409   File "/openedx/venv/lib/python3.11/site-packages/django/core/management/__init__.py", line 416, in execute
4.409     django.setup()
4.409   File "/openedx/venv/lib/python3.11/site-packages/django/__init__.py", line 24, in setup
4.409     apps.populate(settings.INSTALLED_APPS)
4.409   File "/openedx/venv/lib/python3.11/site-packages/django/apps/registry.py", line 124, in populate
4.409     app_config.ready()
4.409   File "/openedx/venv/lib/python3.11/site-packages/casbin_adapter/apps.py", line 12, in ready
4.409     initialize_enforcer(db_alias)
4.409   File "/openedx/venv/lib/python3.11/site-packages/casbin_adapter/enforcer.py", line 67, in initialize_enforcer
4.409     with connect.cursor() as cursor:
4.409          ^^^^^^^^^^^^^^^^
4.409   File "/openedx/venv/lib/python3.11/site-packages/django/utils/asyncio.py", line 26, in inner
4.409     return func(*args, **kwargs)
4.409            ^^^^^^^^^^^^^^^^^^^^^
4.409   File "/openedx/venv/lib/python3.11/site-packages/django/db/backends/base/base.py", line 330, in cursor
4.409     return self._cursor()
4.409            ^^^^^^^^^^^^^^
4.409   File "/openedx/venv/lib/python3.11/site-packages/django/db/backends/dummy/base.py", line 20, in complain
4.409     raise ImproperlyConfigured(
4.409 django.core.exceptions.ImproperlyConfigured: settings.DATABASES is improperly configured. Please supply the ENGINE value. Check settings documentation for more details.
------
Dockerfile:194
--------------------
 192 |     # Pull latest translations via atlas
 193 |     RUN make clean_translations
 194 | >>> RUN ./manage.py lms --settings=tutor.i18n pull_plugin_translations --verbose --repository='openedx/openedx-translations' --revision='release/teak.2' 
 195 |     RUN ./manage.py lms --settings=tutor.i18n pull_xblock_translations --repository='openedx/openedx-translations' --revision='release/teak.2' 
 196 |     RUN atlas pull --repository='openedx/openedx-translations' --revision='release/teak.2'  \
--------------------
ERROR: failed to solve: process "/bin/sh -c ./manage.py lms --settings=tutor.i18n pull_plugin_translations --verbose --repository='openedx/openedx-translations' --revision='release/teak.2'" did not complete successfully: exit code: 1

Now the initialization of the enforcer happens once when it's first used when the application is fully loaded. See https://github.com/officialpycasbin/django-orm-adapter/blob/5196741aadf6060023e933abedaac93e50008cc6/casbin_adapter/enforcer.py#L63-L79 for more details on what the initialization entails.

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[mariajgrimaldi]

I don't think this would be needed.

[BryanttV]

@mariajgrimaldi, thanks for this! I was testing the REST API with these changes, and all works fine except for the permission validation.

I also built the openedx image, and it completed successfully 🚀

[BryanttV]

LGTM!