os/bluestore: turn bluestore zero block detection off by default

os/bluestore: turn bluestore zero block detection off by default

This commit adds a new global config option called `bluestore_zero_block_detection`.
This option is used at a dev level to skip zero bufferlist writes in large-scale
testing scenarios.

Store tests originally written for the BlueStore zero block detection feature
now account for the global config option; these tests will only run if
`bluestore_zero_block_detection` is set to "true".

Fixes: https://tracker.ceph.com/issues/55521
Signed-off-by: Laura Flores <lflores@redhat.com>
(cherry picked from commit 4a8180952c292aa2f8ee656685fcdddc3f0f0a4f)