[CBM] [Objstore] Add new style range files to archive metadata compression

What's the issue?
Instead of having a single range file, we're going to move to having one for each vBucket. This means there will be an additional 1024 files per-bucket by default.

For cloud, we should compress these files in a similar fashion as we do/did with the snapshot/failover files.

(please note that new backups will not need snapshot/failover files i.e. although we're adding new files, we're removing others).