feat(insights): use cached data to help refresh trends query

[aspicer]

This PR makes no user facing changing.

It adds the ability to refresh a cached trends query by using mostly cached data and only pulling data intervals that have occurred since the last fresh of the trend.

For now, it just runs both queries side by side and then compares the results to see how often it is failing.

Concerns running this on production are / potential issues are:

• It kicks off twice as many clickhouse queries for each trends query, although the extra ones look at a much smaller date range. While in testing, it might make sense to delay calculating the cached version of the query until the real one returns the data.
• If new events are streaming in live, the data between the two queries might not be 100% the same. Need to account for this.

[posthog-bot]

This PR hasn't seen activity in a week! Should it be merged, closed, or further worked on? If you want to keep it open, post a comment or remove the stale label – otherwise this will be closed in another week.

[posthog-bot]

This PR was closed due to lack of activity. Feel free to reopen if it's still relevant.