## Bug description

When filtering insights by active feature flags, and trying to select a single feature flag (by using a `contains` selector), events are not being correctly filter (i.e. no events are returned). This presumably happens because the `active_feature_flags` attribute is stored as an array and the operator does not work properly on CH.

## Expected behavior

Relevant events should be loaded.

## How to reproduce

1. Create an insights graph, filter by "Active feature flags" using a contain selector.

Alternatively, just open [this graph](https://app.posthog.com/insights?actions=%5B%7B%22id%22%3A1578%2C%22name%22%3A%22created%20action%22%2C%22type%22%3A%22actions%22%2C%22order%22%3A0%7D%5D&events=%5B%5D&new_entity=%5B%5D&interval=week&date_from=-90d&breakdown=false&breakdown_type&properties=%5B%7B%22key%22%3A%22%24active_feature_flags%22%2C%22value%22%3A%22actions-ux-201012%22%2C%22operator%22%3A%22icontains%22%2C%22type%22%3A%22event%22%7D%5D).

## Environment

Cloud latest version.


#### *Thank you* for your bug report – we love squashing them!

CC @timgl 

ee/clickhouse/models/property.py
if table_name != "":
        table_name += "."
    for idx, prop in enumerate(filters):
        if prop.type == "cohort":
            cohort = Cohort.objects.get(pk=prop.value)
            person_id_query, cohort_filter_params = format_filter_query(cohort)
            params = {**params, **cohort_filter_params}
            final.append(
                "AND {table_name}distinct_id IN ({clause})".format(table_name=table_name, clause=person_id_query)
            )
        elif prop.type == "person":
            filter_query, filter_params = prop_filter_json_extract(prop, idx, "{}person".format(prepend))
            final.append(
                "AND {table_name}distinct_id IN ({filter_query})".format(
                    filter_query=GET_DISTINCT_IDS_BY_PROPERTY_SQL.format(filters=filter_query), table_name=table_name
                )
            )
            params.update(filter_params)
        else:
            filter_query, filter_params = prop_filter_json_extract(
                prop, idx, prepend, prop_var="{}properties".format(table_name)
            )
            final.append(
                "{filter_query} AND {table_name}team_id = %(team_id)s".format(
                    table_name=table_name, filter_query=filter_query
                )
            )
            params.update(filter_params)
    return " ".join(final), params
def prop_filter_json_extract(