## Bug description

When calculating Trends results with an aggregated (e.g. single output, like big number) display type, WAU/MAU don't work. This is because we have an `ACTIVE_USERS_SQL` query for time series display types, but we don't have a version of this for aggregated display types. (See ZEN-1043.)

## How to reproduce

1. Create an insight with a single WAU or MAU series.
2. Switch display type to "Number".
3. Open the "Debug ClickHouse queries" modal from the command palette.
4. See `COUNT(*)` instead of `COUNT(DISTINCT person_id)`.

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posthog/queries/test/test_trends.py
"properties": [{"key": "email", "type": "person", "value": "is_set", "operator": "is_set"}],
                    }
                ),
                self.team,
            )
        self.assertEqual(len(response_with_email_filter), 1)
        self.assertEqual(response_with_email_filter[0]["count"], 2)
    def test_dau_filtering(self):
        sign_up_action, person = self._create_events()
        with freeze_time("2020-01-02"):
            _create_person(team_id=self.team.pk, distinct_ids=["someone_else"])
            _create_event(team=self.team, event="sign up", distinct_id="someone_else")
        with freeze_time("2020-01-04"):
            action_response = Trends().run(
                Filter(data={"actions": [{"id": sign_up_action.id, "math": "dau"}]}), self.team
            )
            response = Trends().run(Filter(data={"events": [{"id": "sign up", "math": "dau"}]}), self.team)
        self.assertEqual(response[0]["data"][4], 1)
        self.assertEqual(response[0]["data"][5], 2)
        self.assertEntityResponseEqual(action_response, response)
    def _create_maths_events(self, values):
        sign_up_action, person = self._create_events()
        _create_person(team_id=self.team.pk, distinct_ids=["someone_else"])
        for value in values:
            _create_event(
                team=self.team, event="sign up", distinct_id="someone_else", properties={"some_number": value}
            )
        _create_event(team=self.team, event="sign up", distinct_id="someone_else", properties={"some_number": None})
        return sign_up_action
    def _test_math_property_aggregation(self, math_property, values, expected_value):