🚚(backend) create a dedicated authentication package

Prepare adding advanced authentication features. Create a dedicated
authentication Python package within the core app.

This code organization will be more extensible.

src/backend/core/authentication/backends.py

@@ -1,4 +1,4 @@
-"""Authentication for the Impress core app."""
+"""Authentication Backends for the Impress core app."""
 
 from django.core.exceptions import SuspiciousOperation
 from django.utils.translation import gettext_lazy as _
@@ -8,7 +8,7 @@ from mozilla_django_oidc.auth import (
     OIDCAuthenticationBackend as MozillaOIDCAuthenticationBackend,
 )
 
-from .models import User
+from core.models import User
 
 
 class OIDCAuthenticationBackend(MozillaOIDCAuthenticationBackend):

src/backend/core/tests/authentication/test_backends.py

@@ -1,11 +1,11 @@
-"""Unit tests for the `get_or_create_user` function."""
+"""Unit tests for the Authentication Backends."""
 
 from django.core.exceptions import SuspiciousOperation
 
 import pytest
 
 from core import models
-from core.authentication import OIDCAuthenticationBackend
+from core.authentication.backends import OIDCAuthenticationBackend
 from core.factories import UserFactory
 
 pytestmark = pytest.mark.django_db

src/backend/impress/settings.py

@@ -206,7 +206,7 @@ class Base(Configuration):
 
     AUTHENTICATION_BACKENDS = [
         "django.contrib.auth.backends.ModelBackend",
-        "core.authentication.OIDCAuthenticationBackend",
+        "core.authentication.backends.OIDCAuthenticationBackend",
     ]
 
     # Django applications from the highest priority to the lowest