## 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/person_query.py
properties_to_query = self._column_optimizer.used_properties_with_type("person")
        if self._inner_person_properties:
            properties_to_query -= extract_tables_and_properties(self._inner_person_properties.flat)
        columns = self._column_optimizer.columns_to_query("person", set(properties_to_query)) | set(self._extra_fields)
        return [(column_name, self.ALIASES.get(column_name, column_name)) for column_name in sorted(columns)]
    def _get_grouped_person_filters(self, prepend: str = "") -> Tuple[str, Dict]:
        return parse_prop_grouped_clauses(
            self._team_id,
            self._inner_person_properties,
            has_person_id_joined=False,
            group_properties_joined=False,
            person_properties_mode=PersonPropertiesMode.DIRECT,
            prepend=prepend,
        )
    def _get_person_filters(self, prepend: str = "") -> Tuple[str, Dict]:
        return parse_prop_grouped_clauses(
            self._team_id,
            self._inner_person_properties,
            has_person_id_joined=False,
            group_properties_joined=False,
            person_properties_mode=PersonPropertiesMode.DIRECT_ON_PERSONS,
            prepend=prepend,
            table_name="person",
        )
    def _get_cohort_query(self) -> Tuple[str, Dict]: