Enable custom styling for elements which are both focused and hovered

[Torvaney]

Currently, when both Element.focused and Element.mouseOver are active on an element, it will resolve to just using the focused styles. This is not always desirable, and it would be great to be have more control over how the combination of these states is resolved.

For example, the highly regarded UK government design system has buttons which appear differently when

• hovered (white text on darker green background)
• focused (black text on yellow background)
• hovered and focused (white text on darker green background, with yellow inner border)

#feature-suggestion