In `faceting.top_values` rank `n` is never used

[datadavev]

https://github.com/cybertec-postgresql/pgfaceting/blob/0da2b9f785b245c1023afa5ba1458ba2bd1fd767/sql/pgfaceting--0.2.0.sql#L588

Should probably be something like:

...
        WHERE rank <= $2 AND table_id = $1
        ORDER BY facet_id, rank, facet_value;
    $sql$,
        faceting._qualified(tdef.schemaname, tdef.facets_table),
        facet_filter)
    USING p_table_id, n;
...