Add sector size as spare selection criterion

Add sector size as spare selection criterion

Add sector size as new spare selection criterion. Assume that 0 means
there is no requirement for the sector size in the array. Skip disks
with unsuitable sector size when looking for a spare to move across
containers.

Signed-off-by: Alexey Obitotskiy <aleksey.obitotskiy@intel.com>
Signed-off-by: Tomasz Majchrzak <tomasz.majchrzak@intel.com>
Signed-off-by: Jes Sorensen <jsorensen@fb.com>