Enhancement: Limit `check` to snapshots selected by filters

The `check` command can now restrict pack verification to snapshots chosen with
the usual snapshot filters (`--tag`, `--host`, `--path`, or explicit snapshot
IDs on the command line).

https://github.com/restic/restic/issues/3326
https://github.com/restic/restic/pull/5469
https://github.com/restic/restic/pull/5644
