Test Renderer for TDD

**Enhancement**
I would like to have a way to render from tests as a way to aid with TDD. Ideally, you would be able to pass an assertion template or component instance to a helper function withing a test file and it would serve that component in a separate window. This would be helpful because you would be able to play with a component in isolation. You could adjust the css and dom structure of an assertion template before updating the component implementation.

**Challenges**
- Build pipeline in tests which includes styles
- Making this work with different test runners
- Tests are shallow while rendering would be deep, might need different setup
- Assertion templates currently don't care about functions in properties but rendering would