Rclone .partial files are not cleaned up for uploads

[atruskie]

When users upload files with rclone (https://rclone.org/commands/rclone_copy/)

partial files have a *.partial extension but the files end up not being cleaned up.

When we investigate the files are missing on disk, so this means our web hooks have missed some event which would have allowed us to destroy the harvest_item record.

e.g.