## 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/trends/breakdown.py
values_arr = get_breakdown_prop_values(
            self.filter,
            self.entity,
            aggregate_operation,
            self.team,
            extra_params=math_params,
            column_optimizer=self.column_optimizer,
            person_properties_mode=self._person_properties_mode,
        )
        
        assert isinstance(self.filter.breakdown, str)
        breakdown_value = self._get_breakdown_value(self.filter.breakdown)
        numeric_property_filter = ""
        if self.filter.using_histogram:
            numeric_property_filter = f"AND {breakdown_value} is not null"
            breakdown_value, values_arr = self._get_histogram_breakdown_values(breakdown_value, values_arr)
        return (
            {"values": values_arr},
            BREAKDOWN_PROP_JOIN_SQL if not self.filter.using_histogram else BREAKDOWN_HISTOGRAM_PROP_JOIN_SQL,
            {"breakdown_value_expr": breakdown_value, "numeric_property_filter": numeric_property_filter},
            breakdown_value,
        )
    def _get_breakdown_value(self, breakdown: str) -> str: