Element.toFront prevents hover events on Firefox 83

[Kasoo]

Element.toFront is implemented as an appendChild call to reposition the element within the DOM.

Similar to previous issues with IE (#225, #527) it appears that on Firefox 83 (and older) this causes the element to be temporarily removed from the DOM and thus prevents it receiving events.

This is notable when calling toFront from scroll event listeners as this will move the elements (and thus require a mouseout), and prevent that event from reaching the element.

[Kasoo]

Attached is a minimal example that replicates the problem on Firefox but works okay on Chrome.

test.html.txt