Add ability to claim hybrid use benefit when creating pools

[MatthewSteeples]

Version: 2.7.0-stable.418

When creating a pool in the Portal, a checkbox exists to enable hybrid use

Save money Save up to 40% with a license you already own. Already have a Windows Server license? Yes No I confirm I have an eligible Windows Server license with Software Assurance to apply this Hybrid Use Benefit.

This adds the following JSON in to the request:

"licenseType": "Windows_Server",

Trying to paste that in to the Batch Explorer has no effect, and there's no option to enable this in the UI. Is it possible to get it added?