[OStore] Improve reported error message in jobs failed during queue cleanup

NOTE: Adding needs discussion label to discuss if all the concerns are described in the ticket.

Problem to solve

As reported in https://gitlab.cern.ch/cta/operations/-/issues/719#note_9673453 we would like to improve the log message shown in the failed job inside the ObjectStore.

Proposal

We already have a dedicated path for the jobs we fail during the queue cleanup of a (REPACKING_PENDING) so it is just a matter of modifying that message.

Alternatively, we can issue a delete of the object after the reporting instead of moving it to the failed queue. We could even do as follows:

• Fail to report to disk buffer -> move it into the failed request. This already happens.
• Success to report to disk buffer -> remove the job.