XDP nuget needs to use Microsoft-standardized prefixes

[mtfriesen]

We need to follow the guide at https://devdiv.visualstudio.com/DevDiv/_wiki/wikis/DevDiv.wiki/11557/Publishing-Microsoft-packages.

The package name needs to be prefixed with Microsoft. to be compliant, among other things.

[nibanks]

This will show up in the next release.