Ensure VM identifier is properly ordered

[brendandixon]

The VMid on Linux can be read from “/sys/class/dmi/id/product_uuid”. The first three components of the UUID must be byte swapped (e.g. 0x01234567 -> 0x67452301) before the value will match the VM id found in the VM’s metadata. Here's an example:

VMid (as seen in poral resource explorer and metadata service)

D0DF4C54-4ECB-4A4B-9954-5BDF3ED5C3B8

VMid as found in “/sys/class/dmi/id/product_uuid” (or from dmidecode)

544CDFD0-CB4E-4B4A-9954-5BDF3ED5C3B8

When making this change, the provisioning code will need to allow for misordered bytes when detecting a possibly new VM.

[brendandixon]

Addressed by #839