## 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/trends/breakdown.py
self,
        entity: Entity,
        filter: Filter,
        team: Team,
        column_optimizer: Optional[ColumnOptimizer] = None,
        using_person_on_events: bool = False,
    ):
        self.entity = entity
        self.filter = filter
        self.team = team
        self.team_id = team.pk
        self.params: Dict[str, Any] = {"team_id": team.pk}
        self.column_optimizer = column_optimizer or ColumnOptimizer(self.filter, self.team_id)
        self.using_person_on_events = using_person_on_events
    @cached_property
    def _person_properties_mode(self) -> PersonPropertiesMode:
        return (
            PersonPropertiesMode.USING_PERSON_PROPERTIES_COLUMN
            if not self.using_person_on_events
            else PersonPropertiesMode.DIRECT_ON_EVENTS
        )
    @cached_property
    def actor_aggregator(self) -> str:
        if self.team.aggregate_users_by_distinct_id:
            return "e.distinct_id"
        return f"{'e' if self._person_properties_mode == PersonPropertiesMode.DIRECT_ON_EVENTS else 'pdi'}.person_id"
    @cached_property
    def _props_to_filter(self) -> Tuple[str, Dict]: