## 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/sql.py
person_id,
        period,
        created_at,
        if(
            dateTrunc(%(interval)s, toTimeZone(toDateTime(created_at, 'UTC'), %(timezone)s)) = period,
            'new',
            if(
                previous_activity + INTERVAL 1 {interval_expr} = period,
                'returning',
                'resurrecting'
            )
        ) AS initial_status,
        period + INTERVAL 1 {interval_expr} = following_activity AS next_is_active,
        previous_activity,
        following_activity
    FROM (
        SELECT
            person_id,
            any(period) OVER (PARTITION BY person_id ORDER BY period ROWS BETWEEN 1 PRECEDING AND 1 PRECEDING) as previous_activity,
            period,
            any(period) OVER (PARTITION BY person_id ORDER BY period ROWS BETWEEN 1 FOLLOWING AND 1 FOLLOWING) as following_activity,
            created_at
        FROM ({events_query})
    )
)
WHERE period_status_pairs.2 != ''
"""
LIFECYCLE_SQL = f"""
WITH
    %(interval)s AS selected_period,