ACTION-58: Add another UIEvent for point-of-regard focus and blur (separate from keyboard focus/blur)

We had something called ATFocus/ATBlur in the original proposal, but I pulled it out of the drafts because it needed more work. My plan is to have something like a pointOfRegardIn and pointOfRegardOut events. Also, an equivalent of document.activeElement that would also apply to to non-focusable nodes. Some of the delay is that I hate the name "point-of-regard" but we haven't come up with anything better. It's not limited to assistive technology. These events would coincide with pointer-triggered events like mouseover/mouseout, keyboard-triggered events like focus/blur, as well as AT-triggered events like screen reader cursor focus, other cursor-driving AT, etc.

If you have any suggestions for syntax, naming conventions, or additional features you'd like to use regarding this idea, please speak up.

Should combine relevant properties from both MouseEvent and FocusEvent, including fromElement/toElement, x/y event coordinates, etc.

Mention in context of mainstream interfaces such as in-page searching, that move a point-of-regard around without necessarily moving keyboard focus.

On the call today I suggest focalPoint and Rich suggested operationalPoint. In hindsight, I don't think operationalPoint is appropriate because you don't provide "operate" on static elements like paragraphs, even though your "point-of-regard" is on it while you're reading.