## 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
"properties": {"$group_2": "company:6"},
                },
                {"event": "sign up", "timestamp": datetime(2020, 1, 2, 13), "properties": {"$group_0": "org:6"}},
                {"event": "sign up", "timestamp": datetime(2020, 1, 3, 15), "properties": {"$group_2": "company:5"}},
            ]
        }
        journeys_for(events_by_person=journey, team=self.team)
        filter = Filter(
            data={
                "date_from": "2020-01-01T00:00:00Z",
                "date_to": "2020-01-12",
                "events": [{"id": "sign up", "name": "sign up", "type": "events", "order": 0}],
                "properties": [
                    {"key": "industry", "value": "finance", "type": "group", "group_type_index": 0},
                    {"key": "name", "value": "six", "type": "group", "group_type_index": 2},
                ],
            }
        )
        with override_instance_config("PERSON_ON_EVENTS_ENABLED", True):
            response = Trends().run(filter, self.team)
            self.assertEqual(len(response), 1)
            self.assertEqual(response[0]["count"], 1)
            self.assertEqual(response[0]["data"], [0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0])
            filter = filter.with_data({"date_from": "2020-01-02T00:00:00Z", "date_to": "2020-01-02T00:00:00Z"})
            entity = Entity({"id": "sign up", "name": "sign up", "type": "events", "order": 0})
            res = self._get_trend_people(filter, entity)
            self.assertEqual(res[0]["distinct_ids"], ["person1"])
class TestTrendUtils(ClickhouseTestMixin, APIBaseTest):
    maxDiff = None
    def test_get_cached_result_no_cache(self):