## 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
FROM ({event_query}) GROUP BY person_id
"""
TOP_ELEMENTS_ARRAY_OF_KEY_SQL = """
SELECT groupArray(value) FROM (
    SELECT
        {value_expression},
        {aggregate_operation} as count
    FROM events e
    {person_join_clauses}
    {groups_join_clauses}
    {sessions_join_clauses}
    WHERE
        team_id = %(team_id)s {entity_query} {parsed_date_from} {parsed_date_to} {prop_filters} {null_person_filter}
    GROUP BY value
    ORDER BY count DESC, value DESC
    LIMIT %(limit)s OFFSET %(offset)s
)
"""
HISTOGRAM_ELEMENTS_ARRAY_OF_KEY_SQL = """
SELECT {bucketing_expression} FROM (
    SELECT
        {value_expression},
        {aggregate_operation} as count
    FROM events e
    {person_join_clauses}
    {groups_join_clauses}
    {sessions_join_clauses}
    WHERE
        team_id = %(team_id)s {entity_query} {parsed_date_from} {parsed_date_to} {prop_filters} {null_person_filter}
    GROUP BY value