Auto merge of #20865 - gterzian:improve_spec_compliance_window_close, r=cbrewster

improve spec compliance of window.close

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Improve the spec compliance of https://html.spec.whatwg.org/multipage/window-object.html#dom-window-close, mainly by implementing the steps related to [closing a browsing context](https://html.spec.whatwg.org/multipage/window-object.html#close-a-browsing-context)

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