Importing Multiple Versions of the Same DSC Resource should be Tested

[alx9r]

I'm not sure whether ZeroDSC resource invokers behave correctly when multiple resource invokers of the same resource but with different versions are created. It should be confirmed that each resource invoker indeed imports the correct version. This should be tested for both MOF- and class-based resources. I think there is already an appropriate class-based test stub resource with multiple versions. Likely a new MOF-based test stub resource with multiple versions needs to be created for testing.