Add nvmecontrol sanitize command.

It allows to delete all user data from NVM subsystem in one of 3 methods.
It is a close equivalent of SCSI SANITIZE command of camcontrol sanitize,
so I tried to keep arguments as close as possible.

While there, fix supported sanitize methods reporting in identify.

MFC after: 2 weeks
Relnotes: yes
Sponsored by: iXsystems, Inc.