Intercepted navigations are not reported to WebDriver BiDi

[OrKoN]

As pointed out by @domenic in whatwg/html#10587 (comment):

In https://html.spec.whatwg.org/multipage/browsing-the-web.html#navigate, step 21.5, the page can intercept the navigation request and abort it. This is currently not reported to the WebDriver client. From the client perspective, the navigationStarted event is emitted without any further events.

We probably want to emit either the navigation failed or the navigation aborted event.