## 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)`.

#### *Thank you* for your bug report – we love squashing them!

posthog/queries/test/test_trends.py
_create_person(team_id=self.team.pk, distinct_ids=["person_1"], properties={"name": "John"})
        _create_person(team_id=self.team.pk, distinct_ids=["person_2"], properties={"name": "Jane"})
        _create_event(event="event_name", team=self.team, distinct_id="person_1", properties={"$browser": "Safari"})
        _create_event(event="event_name", team=self.team, distinct_id="person_2", properties={"$browser": "Chrome"})
        _create_event(event="event_name", team=self.team, distinct_id="person_2", properties={"$browser": "Safari"})
        cohort = _create_cohort(
            team=self.team,
            name="cohort1",
            groups=[{"properties": [{"key": "name", "value": "Jane", "type": "person"}]}],
        )
        response = Trends().run(
            Filter(
                data={
                    "properties": [{"key": "id", "value": cohort.pk, "type": "cohort"}],
                    "events": [{"id": "event_name"}],
                },
                team=self.team,
            ),
            self.team,
        )
        self.assertEqual(response[0]["count"], 2)
        self.assertEqual(response[0]["data"][-1], 2)
    def test_response_empty_if_no_events(self):