tooltip position error when editor dom node with transform style

[deepkolos]

Describe the issue

Browser and platform

Edge

Reproduction link

No response

[marijnh]

I incorrectly assumed Chrome would behave the same as Firefox in case of a fixed position element inside a transformed element, and give it a meaningful offsetParent property. But it seems to just always set the offsetParent on fixed elements to null, requiring a more roundabout detection of the situation where a transform breaks fixed positioning of the tooltips. Attached patch should help with this.