[RFE] Add support for Move and Rebuild Phase to umount Dell virtual media

[sadsfae]

This is an RFE for adding the same support to --move-hosts that SuperMicro has for unmounting virtual media.

This is supported in iDRAC versions 6.0 and higher only

if int(data["FirmwareVersion"].replace(".","")) >= 6000000:

We should attempt to do this and fail / continue with an error message noting the version isn't high enough should some systems not meet this criteria.