## 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/trends_event_query.py
is_entity_per_user = self._entity.math == UNIQUE_USERS
        if (
            is_entity_per_user and not self._aggregate_users_by_distinct_id
        ) or self._column_optimizer.is_using_cohort_propertes:
            self._should_join_distinct_ids = True
    def _get_date_filter(self) -> Tuple[str, Dict]:
        date_filter = ""
        query_params: Dict[str, Any] = {}
        query_date_range = QueryDateRange(self._filter, self._team)
        parsed_date_from, date_from_params = query_date_range.date_from
        parsed_date_to, date_to_params = query_date_range.date_to
        query_params.update(date_from_params)
        query_params.update(date_to_params)
        self.parsed_date_from = parsed_date_from
        self.parsed_date_to = parsed_date_to
        if self._entity.math in [WEEKLY_ACTIVE, MONTHLY_ACTIVE]:
            active_user_format_params, active_user_query_params = get_active_user_params(
                self._filter, self._entity, self._team_id
            )
            self.active_user_params = active_user_format_params
            query_params.update(active_user_query_params)
            date_filter = "{parsed_date_from_prev_range} {parsed_date_to}".format(
                **active_user_format_params, parsed_date_to=parsed_date_to
            )
        else:
            date_filter = "{parsed_date_from} {parsed_date_to}".format(
                parsed_date_from=parsed_date_from, parsed_date_to=parsed_date_to
            )
        return date_filter, query_params
    def _get_entity_query(self) -> Tuple[str, Dict]: