Pseudos: Add support for psuedo-selectors

[sinclairnick]

Currently, Pseudo-selectors are not supported directly. They can be applied via <Style/> tags. Maybe this is sufficient. But a more approachable DX may be preferable for adding psuedo styles, given we can narrow functionality to that which works. For example, perhaps :hover is more supported than :not(:focus-visible). The former could be a first-class property on appropriate components while the latter could be reserved for explicit progressive enhancement via explicit style tag usage.