Statistics purge may be too conservative

[j-chmielewski]

Related issues: #874, #1037

After investigating the above issues, it appears that on Windows, even when statistics purging is working correctly, the database can still accumulate enough records to cause excessive database activity and high disk writes.
We should try to reproduce this, preferably on Windows, and measure database growth and disk usage over time. We should also evaluate whether the statistics retention window is too long and should be shortened.

[j-chmielewski]

@jakub-tldr test scenario

• run new client on an old database with > 28h of stats data, the client should trim the location_stats table rows to last 28h