Validate volume WWN upon connect

There are cases where os-brick connects a volume to a host, but in effect the wrong volume is connected.
For example, if a volume disconnect left a device on the host, and in another connection a volume gets the same LUN, the new connection gets the same device and the OS thinks that the original volume reconnected. Thus we can get situations where (1) pending writes to the original volume are flushed to the new one resulting in corruption, (2) the wrong volume is attached to a VM, or (3) the same volume is attached to 2 different VMs, resulting in corruption.
We should therefore add validation to ensure the connected device in fact points to the expected volume.