When restoring a snapshot (on startup, installed from the leader, or during recovery) the logs are extremely terse. There are typically bookend messages indicating that a restore is going to happen, and that it is complete, but there's a big dead space in the middle.

For small snapshots this is probably fine, but for larger multi-GB snapshots this can stretch out and can be unnerving as an operator to know if it's stuck or still making progress.

This PR adjusts the logging to indicate a simple progress log message every 10s about overall completion in bytes-consumed.