Re-enable PointerEvents in Firefox once they fix their implementation

In #6999 we disabled PointerEvents in Firefox completely because their implementation seems broken. There is some discussion of this in #6372 (along with reproducible bugs)

Once Firefox improves their implementation, we should re-enable it (and confirm none of the bugs in the linked issue still exists)

Start by reviewing the PointerEvents disabling change referenced in #6999 and the discussion and reproducible Firefox bugs in #6372. Confirm that Firefox's implementation has improved and that the reported bugs no longer occur; done means PointerEvents is re-enabled without those regressions.

Written by the indexing model from the issue text.