Add stubbed support for decom for testing
Stubbing out BIOS settings
Set path for ddcli

ddcli is usable in /mnt/bin/ddcli in our image, and is coded to use
that. Relying on $PATH is not awesome as we will eventually need to
specify CWD for binaries as we move along.
Typo
Fixing ordering and adding states for decom
Fix naming issue
Reboot not required for secure erase
Fix priorities
Fixing error and adding version string
erase_device -> erase_devices
int != str
Refactor and implement new BlockDevice

Refactored listing LSI devices so it can be used in the
LSI firmware method. Uses the improved BlockDev implemented here:
https://review.openstack.org/#/c/108040/. Using the model attribute of the
improved BlockDev to match the device to a controller.