## 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
BREAKDOWN_INNER_SQL = """
SELECT
    {aggregate_operation} as total,
    {interval_annotation}(toTimeZone(toDateTime(timestamp, 'UTC'), %(timezone)s) {start_of_week_fix}) as day_start,
    {breakdown_value} as breakdown_value
FROM events e
{person_join}
{groups_join}
{sessions_join}
{breakdown_filter}
{null_person_filter}
GROUP BY day_start, breakdown_value
"""
VOLUME_PER_ACTOR_BREAKDOWN_INNER_SQL = """
SELECT
    {aggregate_operation} AS total, day_start, breakdown_value
FROM (
    SELECT
        COUNT(*) AS intermediate_count,
        {aggregator},
        {interval_annotation}(toTimeZone(toDateTime(timestamp, 'UTC'), %(timezone)s) {start_of_week_fix}) AS day_start,
        {breakdown_value} as breakdown_value
    FROM events AS e
    {person_join}
    {groups_join}
    {sessions_join}
    {breakdown_filter}
    {null_person_filter}
    GROUP BY {aggregator}, day_start, breakdown_value
)