t/zbd: add test cases for zone_reset_threshold option

t/zbd: add test cases for zone_reset_threshold option

The zone_reset_threshold option works for multiple jobs only when the
jobs have same write range. Add three test cases to confirm that the
option works for multiple jobs as expected. The first test case checks
that different write ranges are reported as an error. The second test
case checks that multiple write jobs work when they have same write
range. The third test case checks that a read job and a write job work
when they have different IO ranges.

Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Reviewed-by: Niklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: Vincent Fu <vincent.fu@samsung.com>