✨(models/api) add RBAC on templates linking accesses to a team name

We want to be able to control who can access a template via roles.
I added this feature on the TeamAccess model assuming that the teams
to which a user belongs can be retrieved via a `get_teams` method on
the user model. The idea is that this method will get the teams either
via a call to an external API or directly from the OIDC token upon
user login. This list of teams will probably have to be cached for
each user.

src/backend/core/factories.py

@@ -41,12 +41,12 @@ class TemplateFactory(factory.django.DjangoModelFactory):
         if create and extracted:
             for item in extracted:
                 if isinstance(item, models.User):
-                    TemplateAccessFactory(template=self, user=item)
+                    UserTemplateAccessFactory(template=self, user=item)
                 else:
-                    TemplateAccessFactory(template=self, user=item[0], role=item[1])
+                    UserTemplateAccessFactory(template=self, user=item[0], role=item[1])
 
 
-class TemplateAccessFactory(factory.django.DjangoModelFactory):
+class UserTemplateAccessFactory(factory.django.DjangoModelFactory):
     """Create fake template user accesses for testing."""
 
     class Meta:
@@ -55,3 +55,14 @@ class TemplateAccessFactory(factory.django.DjangoModelFactory):
     template = factory.SubFactory(TemplateFactory)
     user = factory.SubFactory(UserFactory)
     role = factory.fuzzy.FuzzyChoice([r[0] for r in models.RoleChoices.choices])
+
+
+class TeamTemplateAccessFactory(factory.django.DjangoModelFactory):
+    """Create fake template team accesses for testing."""
+
+    class Meta:
+        model = models.TemplateAccess
+
+    template = factory.SubFactory(TemplateFactory)
+    team = factory.Sequence(lambda n: f"team{n}")
+    role = factory.fuzzy.FuzzyChoice([r[0] for r in models.RoleChoices.choices])