HyperVDsc: should support IovEnabled property

[dcuomo]

Details of the scenario you tried and the problem that is occurring

vSwitch can not be created with the IovEnabled property set to true using this resource

Verbose logs showing the problem

N/A - New capability not currently included in this resource

Suggested solution to the issue

When creating the vSwitch, a new boolean param should be added ($EnableIov)
If true, new-vmswitch command e.g.
New-VMSwitch -EnableIov $true

if $false or not specified, no modification to the new-vmswitch in the set is necessary

this can be tested by validating the value of (Get-VMSwitch -Name ).IovEnabled

The DSC configuration that is used to reproduce the issue (as detailed as possible)

N/A - New capability not currently included in this resource

The operating system the target node is running

Windows Server 2016 or Windows Server 2019

Version and build of PowerShell the target node is running

N/A

Version of the DSC module that was used ('dev' if using current dev branch)

Master