🐛(backend) fix dysfunctional permissions on document create

When creating a document access, users were benefitting on the targeted
document from the highest access right they have among all documents.
This is because we forgot to filter on the document ID when retrieving
the role of the user. We improved all tests to secure this issue.

src/backend/core/factories.py

@@ -27,6 +27,24 @@ class UserFactory(factory.django.DjangoModelFactory):
     language = factory.fuzzy.FuzzyChoice([lang[0] for lang in settings.LANGUAGES])
     password = make_password("password")
 
+    @factory.post_generation
+    def with_owned_document(self, create, extracted, **kwargs):
+        """
+        Create a document for which the user is owner to check
+        that there is no interference
+        """
+        if create and (extracted is True):
+            UserDocumentAccessFactory(user=self, role="owner")
+
+    @factory.post_generation
+    def with_owned_template(self, create, extracted, **kwargs):
+        """
+        Create a template for which the user is owner to check
+        that there is no interference
+        """
+        if create and (extracted is True):
+            UserTemplateAccessFactory(user=self, role="owner")
+
 
 class DocumentFactory(factory.django.DjangoModelFactory):
     """A factory to create documents"""