ceph-volume: has_bluestore_label checks all bluestore label replica offsets

ceph-volume: has_bluestore_label checks all bluestore label replica offsets

BlueStore replicates the block device label at fixed offsets (0 and
multiples of 1Gb up to 1000gb). has_bluestore_label() only read the
first 22 bytes, so disks with a wiped primary label but intact
replicas are missed.

with this commit, has_bluestore_label() scans each known offset with
seek/read and compares the ASCII prefix as bytes.

Fixes: https://tracker.ceph.com/issues/76060
Signed-off-by: Guillaume Abrioux <gabrioux@ibm.com>