Add some missing HTMLElement subclasses

Summary:
Adds or refines missing subclasses of `HTMLElement`:
- https://developer.mozilla.org/en-US/docs/Web/API/HTMLAreaElement
- https://developer.mozilla.org/en-US/docs/Web/API/HTMLBodyElement
- https://developer.mozilla.org/en-US/docs/Web/API/HTMLDataElement
- https://developer.mozilla.org/en-US/docs/Web/API/HTMLDataListElement
- https://developer.mozilla.org/en-US/docs/Web/API/HTMLDialogElement
- https://developer.mozilla.org/en-US/docs/Web/API/HTMLEmbedElement
- https://developer.mozilla.org/en-US/docs/Web/API/HTMLHeadElement
- https://developer.mozilla.org/en-US/docs/Web/API/HTMLHtmlElement
- https://developer.mozilla.org/en-US/docs/Web/API/HTMLMapElement
- https://developer.mozilla.org/en-US/docs/Web/API/HTMLMeterElement
- https://developer.mozilla.org/en-US/docs/Web/API/HTMLModElement
- https://developer.mozilla.org/en-US/docs/Web/API/HTMLObjectElement
- https://developer.mozilla.org/en-US/docs/Web/API/HTMLParamElement
- https://developer.mozilla.org/en-US/docs/Web/API/HTMLPictureElement
- https://developer.mozilla.org/en-US/docs/Web/API/HTMLProgressElement
- https://developer.mozilla.org/en-US/docs/Web/API/HTMLQuoteElement
- https://developer.mozilla.org/en-US/docs/Web/API/HTMLTableColElement
- https://developer.mozilla.org/en-US/docs/Web/API/HTMLTimeElement
- https://developer.mozilla.org/en-US/docs/Web/API/HTMLTitleElement
- https://developer.mozilla.org/en-US/docs/Web/API/HTMLTrackElement

Reviewed By: mroch

Differential Revision: D7165025

fbshipit-source-id: 62376cb7aeb9ed809efa96d8814e38b03acc26c2