Add tests that test the HTML result of the XML transformation

[JohnMcGuinness]

After discussing with Mark, there apparently were tests in the client side that tested this in the past, when the XSLT transform was done in the browser. However when the XSLT transform was moved to the backend those tests were not ported along with the transform itself.

The tests should be reinstated to assist with any future process of removing the XSLT transform so that we can have confidence that the HTML being sent to the client isn't changing.