scsi: scsi_debug: First fixes for tapes

Patch includes the following:

 - Enable MODE SENSE/SELECT without actual page (to read/write only the
   Block Descriptor)

 - Store the density code and block size in the Block Descriptor (only
   short version for tapes)

 - Fix REWIND not to use the wrong page filling function

Signed-off-by: Kai Mäkisara <Kai.Makisara@kolumbus.fi>
Link: https://lore.kernel.org/r/20250213092636.2510-2-Kai.Makisara@kolumbus.fi


Reviewed-by: John Meneghini <jmeneghi@redhat.com>
Tested-by: John Meneghini <jmeneghi@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>