scsi: scsi_debug: Add ZBC zone commands

Add support for the 5 ZBC commands and enough functionality to emulate a
host-managed device with one conventional zone and a set of sequential
write-required zones up to the disk capacity.

Link: https://lore.kernel.org/r/20200422104221.378203-3-damien.lemoal@wdc.com
Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>