## 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
self,
        filter: Union[Filter, PathFilter, RetentionFilter, StickinessFilter],
        team_id: int,
        column_optimizer: Optional[ColumnOptimizer] = None,
        cohort: Optional[Cohort] = None,
        *,
        entity: Optional[Entity] = None,
        extra_fields: List[ColumnName] = [],
    ) -> None:
        self._filter = filter
        self._team_id = team_id
        self._entity = entity
        self._cohort = cohort
        self._column_optimizer = column_optimizer or ColumnOptimizer(self._filter, self._team_id)
        self._extra_fields = set(extra_fields)
        if self.PERSON_PROPERTIES_ALIAS in self._extra_fields:
            self._extra_fields = self._extra_fields - {self.PERSON_PROPERTIES_ALIAS} | {"properties"}
        properties = self._filter.property_groups.combine_property_group(
            PropertyOperatorType.AND, self._entity.property_groups if self._entity else None
        )
        self._inner_person_properties = self._column_optimizer.property_optimizer.parse_property_groups(
            properties
        ).inner
    def get_query(self, prepend: str = "", paginate: bool = False) -> Tuple[str, Dict]: