Replace platform with generic components from @thepassle

[gregwhitworth]

@thepassle has begun creating WIA-ARIA adhering generic components/controls. They can be seen here: https://github.com/thepassle/generic-components/

Since we've begun working on the select we end up spinning up little testcases to test out aspects of the component, and it would be good to iterate on actual web components. In speaking with @thepassle he liked the overall goal of Open UI and agreed to move the generic components into Open UI and plans to, time willing, help us further build out the generic component set of web components while we further improve the Open UI control definitions.

Thanks a ton to @thepassle

[gregwhitworth]

As noted in the PR, I do think there is value in the spirit of this work but I think that the base components should be built alongside the Open UI spec. As we make progress on that front we'll continue to evaluate the plethora of tooling that Open-WC provides to see if there is value in leveraging them as the project matures.