Remove api.HTMLBodyElement.orientationchange event

[queengooborg]

This PR adapts the orientationchange event of the HTMLBodyElement API to conform to the new events structure.

Note: there are no MDN pages associated with these events, so there will be no corresponding content PR. Any broken MDN URLs in BCD have been removed.

[foolip]

Per https://compat.spec.whatwg.org/#windoworientation-interface this event should be fired the Window object, but Safari also fires it at HTMLBodyElement.

Some testing to check if an event handler added with document.body.addEventListener('orientationchange', callback) will ever be called would be good.

If it's only Safari that ever fires the event at HTMLBodyElement, then the data should be updated and "standard_track" set to false. Or maybe we just remove this entry, I'm not sure it's useful.

[Elchi3]

I think we should remove this entry. If we want, we can add a note to api.window.orientationchange_event for Safari and say that there is non-standard behavior implemented that makes the event also fire at HTMLBodyElement.

[Elchi3]

@queengooborg do you want to remove this entry in this PR?