Revisit JetStream Backup and Restore

[ripienaar]

Proposed change

The backup/restore feature needs an entire revisit, probably completely scrapping what we have.

Some, but not all, high level goals:

• It should be resilient for very large backups and restores to better handle latency, fc, retransmission etc
• It should handle disk space better
• It should support incremental backups and restores
• It should be much safer and produce a more consistent result ideally around a specific point in time up to a stated certain sequence or ts
• Old backups should be supported or be convertible

Use case

Improve reliability

Contribution

No response