[UR][L0v2] Validate queue priority range and priority class
The UR API guarantees that the queue priority range contains the default
priority 0, but the adapter reported the driver range as is. Query the
range once per device and report priority levels as unsupported if the
range doesn't contain 0.
Also assert that a priority level is only combined with the normal
priority class, which the driver would otherwise silently override,
clarify the copy offload comment and log a missing level as "none".
