Add LayoutTransformControl Sample

[michael-hawker]

I'm submitting a...

[ ] Regression (a behavior that used to work and stopped working in a new release)
[ ] Bug report  <!-- Please search GitHub for a similar issue or PR before submitting -->
[ ] Feature request <!-- Please file a UserVoice request and include the link below https://wpdev.uservoice.com/forums/110705-universal-windows-platform/category/193402-uwp-community-toolkit -->
[x] Sample app request
[ ] Documentation issue or request
[ ] Question of Support request => Please do not submit support request here, instead see https://github.com/Microsoft/UWPCommunityToolkit/blob/master/contributing.md#question

UserVoice link

Historical Reference: https://wpdev.uservoice.com/forums/110705-universal-windows-platform/suggestions/4173675-add-layouttransform-to-windows-store-xaml-just-lik

Current behavior

We added the LayoutTransformControl last year, but no sample was added.

Expected behavior

Have a sample which shows how to use it.

[Odonno]

Indeed, it was added to make the Header (vertical/horizontal) of the Expander control.

[Odonno]

Let's go for it.