Sort by full path name instead of by GUID when importing

Sort by full path name instead of by GUID when importing

Preferentially sort by the full path name instead of GUID when determining
which device links to use.  This helps ensure that the pool vdevs are named
consistently when multiple links for a device appear in the same directory.
For example, the /dev/disk/by-id/scsi* and /dev/disk/by-id/wwn* links.

Reviewed-by: Alek Pinchuk <apinchuk@datto.com>
Reviewed-by: Richard Elling <Richard.Elling@RichardElling.com>
Authored-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Kash Pande <kash@tripleback.net>
Closes #8108
Closes #8440