OCP: implement MAC collision detection

[bennyz]

Existing sources have an attempt to preserve the existing MAC addresses from the source, this attempt is not perfect as it relies on checking the MAC address of existing VMs in the target cluster. This may not always work as the forklift may not be able to list all VMs.

In addition, we need to provide the user the option to choose not to preserve MAC addresses

[rajgani]

Was there any solution around this, we have a similar use case for not to preserve the Mac Address for the Migrated VM ?