## Bug description

<img width="696" alt="Screen Shot 2021-09-16 at 2 37 41 PM" src="https://user-images.githubusercontent.com/13460330/133689529-c4fffc7f-53f8-494e-b7a8-7fb656fd50e6.png">

## Expected behavior

Bars and labels always show on top of axes and gridlines.

## How to reproduce

1. https://app.posthog.com/insights?insight=FUNNELS&properties=%5B%5D&filter_test_accounts=false&events=%5B%7B%22id%22%3A%22%24pageview%22%2C%22name%22%3A%22%24pageview%22%2C%22type%22%3A%22events%22%2C%22order%22%3A0%7D%2C%7B%22id%22%3A%22%24pageview%22%2C%22name%22%3A%22%24pageview%22%2C%22type%22%3A%22events%22%2C%22order%22%3A1%7D%2C%7B%22id%22%3A%22%24pageview%22%2C%22name%22%3A%22%24pageview%22%2C%22type%22%3A%22events%22%2C%22order%22%3A2%7D%5D&actions=%5B%5D&exclusions=%5B%5D&interval=day&funnel_from_step=0&funnel_to_step=1&new_entity=%5B%5D&funnel_viz_type=time_to_convert&display=FunnelViz

## Environment

- [X] PostHog Cloud
- [X] self-hosted PostHog (ClickHouse-based), version/commit: _please provide_
- [X] self-hosted PostHog (Postgres-based, legacy), version/commit: _please provide_

## Additional context



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

ee/clickhouse/queries/funnels/funnel_time_to_convert.py
/* bin_count is only made available as an identifier if it had to be calculated */
                {
                    f"( SELECT {bin_count_identifier} FROM histogram_params ) AS {bin_count_identifier},"
                    if bin_count_expression else ""
                }
                ( SELECT from_seconds FROM histogram_params ) AS histogram_from_seconds,
                ( SELECT to_seconds FROM histogram_params ) AS histogram_to_seconds,
                ( SELECT average_conversion_time FROM histogram_params ) AS histogram_average_conversion_time
            SELECT
                bin_from_seconds,
                person_count,
                histogram_average_conversion_time AS average_conversion_time
            FROM (
                /* Calculating bins from step runs */
                SELECT
                    histogram_from_seconds + floor(({steps_average_conversion_time_expression_sum} - histogram_from_seconds) / bin_width_seconds) * bin_width_seconds AS bin_from_seconds,
                    count() AS person_count
                FROM step_runs
                GROUP BY bin_from_seconds
            ) results
            RIGHT OUTER JOIN (
                /* Making sure bin_count bins are returned */
                /* Those not present in the results query due to lack of data simply get person_count 0 */
                SELECT histogram_from_seconds + number * bin_width_seconds AS bin_from_seconds FROM system.numbers LIMIT {bin_count_identifier} + 1
            ) fill
            USING (bin_from_seconds)
            ORDER BY bin_from_seconds
            SETTINGS allow_experimental_window_functions = 1"""
        return query