Improve downloader logs on hash mismatch

[steven-sheehy]

Problem

As an operator, it's difficult to determine from the logs which actual signature file is most likely the one missing when encountering a hash mismatch exception. This is because the importer will attempt to skip over and log many failed files until it finds the correct one.

Solution

Enhance the Downloader to add the name of the last processed stream file name as well as the earliest signature file in the batch of signatures listed from the bucket when a HashMismatchException is caught.

Alternatives

No response