[director] Scan should detect when a disk is no longer attached to a vm [#fixes 45815909]

- Check if the list_disk call timeouts, as it indicates it's unable to find the device.
- Add a new resolution to reattack disk and reboot vm (as some kernel reassigns the device name to the next available, so we should reboot the vm to get the correct device name).
- Use the Bosh agent convention device names at the OpenStack CPI