Move script to install Windows 10 SDK to CI toolkit

[mokagio]

Studio and another of our apps require the Windows 10 SDK to build the AppX package. They duplicate the script that install it.

We ought to:

• Have the SDK already available as part of what should be our custom Windows image; and
• Make the script available via the CI toolkit so it's DRY and easily available to other clients

Before we do this, we'll need to figure out the tests issues in #100

[mokagio]

See a8c-ci-toolkit-buildkite-plugin #144

[ParaskP7]

RTO: @mokagio I noticed that this In Progress issue is missing a Start Date and an ETA, a requirement as per the definition, not sure about the need to attach an RFC or/and Project Thread as well. 🙏

PS: I am not sure if we can also add the CI Toolkit component to it. 🤔

[mokagio]

Done via #144