Michael Manganiello 045aa64558 cmd/copy: Prefix hostname to snapshot display output
This change better resembles the output generated by `Snapshot.String()`,
which includes both username and hostname.

Closes #4506

Before:

```
$ restic copy --from-repo /srv/restic-repo
repository 3666882b opened (version 2, compression level auto)
repository 0085c387 opened (version 2, compression level auto)
created new cache in /home/mike/.cache/restic
[0:00] 100.00%  1 / 1 index files loaded
[0:00]          0 index files loaded

snapshot 32b39a20 of [/home/mike/data] at 2023-10-21 16:01:13.979948154 -0300 -03)
  copy started, this may take a while...
[0:00] 100.00%  1 / 1 packs copied
snapshot 10331fdd saved
```

After:

```
$ restic copy --from-repo /srv/restic-repo
repository 3666882b opened (version 2, compression level auto)
repository 0085c387 opened (version 2, compression level auto)
[0:00] 100.00%  1 / 1 index files loaded
[0:00]          0 index files loaded

snapshot 32b39a20 of [/home/mike/data] at 2023-10-21 16:01:13.979948154 -0300 -03 by mike@desktop)
  copy started, this may take a while...
[0:00] 100.00%  1 / 1 packs copied
snapshot a67bd1ee saved
```
2024-01-06 20:20:46 +01:00
..
2020-02-13 00:09:37 +01:00
2018-02-05 20:48:48 +01:00
2023-10-24 20:02:55 +02:00
2023-10-27 18:56:32 +02:00
2023-10-27 18:56:32 +02:00
2023-03-22 17:37:58 +01:00
2022-07-08 20:05:35 +02:00
2023-12-06 13:11:55 +01:00
2023-05-01 14:56:42 +02:00