RFC: allow command line to specify controller + lun/nsid

[mattkur]

I was surprised that adding additional uh-nvme disks didn't add multiple controllers, so add that capability.

I lost steam when trying to hook this up to the openvmm storage builder, but sending this out as an RFC on the command line options format.

[github-actions[bot]]

⚠️ Unsafe Code Detected

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