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

Suggestion: return (axs.properties.getAriaProperties(element) != null)
(I realise this is semantically equivalent, but I think this makes the reasons clearer. Up to you.)