borg check should take "notes"

Many borg users will use regularly scheduled borg create and borg check jobs to create and verify their backups.

If there is a lot of data in the repo, borg check will take a long time, but that should not be a problem because it runs unattended and also its runtime can be limited.

BUT, if there are issues with a repository (e.g. the check job detecting something), usually the repo admin will try to fix issues interactively and interactive operations should be fast.

That means:

• we should not need to run a full borg check again (processing all packs / all objects in the repo)
• borg check [--repair] should re-use intelligence that previous borg check runs have gathered (e.g. IDs of corrupt packs, IDs of corrupt or missing objects)
• borg create could have a special treatment (re-chunk them!) for paths of files that were noted as corrupted or containing missing chunks by borg check.