nvme: Add more validation around feature parameters

[luqmana]

A few notes on validation here that I think we want to check:

• cdw11 is used by features to control behavior on a per-feature basis. I would like to see us constrain this to be zero and drop an error if not so we can add additional behavior over time.
• I don't see any logic checking the value of the CDW10 feature selector. Is that somewhere I missed? It looks like that's being dropped in AdminCmd::parse. Doesn't have to be fixed in this change, but probably should be a follow up for us there.
• I think it's okay that we're not checking the data pointer since the spec says it's ignored when the feature doesn't use it, which means it can have garbage.
• I feel less confident in cdw14 with feature by uuid, but I think it's probably okay in spirit.

Originally posted by @rmustacc in #1060 (comment)