More ports from aria-toolkit and enhancements

* Implicit semantics
* More audits:
 * RequiredOwnedAriaRoleMissing
 * DuplicateId
 * RoleNotScoped
 * BadAriaAttribute
 * UnsupportedAriaAttribute
 * AriaOnReservedElement
* Fixed BadAriaRole audit to handle abstract roles
* Several supporting changes and optimizations to utility methods and constants.
* A few minor formatting tweaks

This name is not as descriptive as it could be... - perhaps 'getNativelySupportedAttributes'? I realise that's pretty long, but I think we can deal.