Ensure LMS passes correct group_id when querying content

TNL-23
I think this would be more readable if the argument order matched the test method name and if the non-varying argument (mock_request) came first:

`self.call_view(mock_request, "cohorted_topic", self.student, None, pass_group_id=False)`

We should probably also add a definition for the call_view function just for documentation; it can raise NotImplementedError.