[Research] How to restore a cloud backup with the `gitlab-backup-cli`?

Things to consider:

• PITR: how will we choose which backups from each datatype to restore?
• Design of a manifest of the components and the time span that can be restored?
  • how will this data be presented? JSON?

More questions from @andrashorvath !155246 (comment 1938999854)

Questions I'd like answered:

• is the goal to restore-in-place, or also restore-on-the-side?
• can backups taken in Portable or Cloud mode be restored to the other environment (is this a migration gateway for example?)