Add support for the new search element

[scottaohara]

ARIA in HTML has been updated to reflect the addition of the search element to the HTML specification.

to save one having to follow the link, the allowed roles (likely to mitigate initial developer misuse / correct for existing custom search elements that may have been used) for the search element are:
form, group, none, presentation, region and with the allowed but not recommended use of the search role, as well.

[aliunwala]

Triage:
We will prioritize this in a future sprint.

https://html.spec.whatwg.org/#the-search-element
4.4.15 The search element

Also here https://w3c.github.io/html-aria/ :

[ErickRenteria]

Validated