Ensure TestContext registeres all dependencies as services, provide them options

[egil]

Things like the markup parser and markup comparer can be passed options and configuration or replaced entirely to change their behavior. If they are registered by default in the test service provider, they can be replaced or accessed by the test.

In addition to this, we should consider making it possible to pass options to the drivers services though the aspnetcore options pattern

[egil]

Created a simple extension method used in all the places web test contexts are created, that registers the HtmlParser, HtmlComparer, and the ITestRenderer.