browsingContext.navigate/reload HTML integration needs updating

[foolip]

After whatwg/html#6315 we need to make some changes to await a navigation, used in the browsingContext.navigate and browsingContext.reload commands.

WebDriver BiDi generates and passes in a navigation id to HTML's navigate algorithm, but that doesn't have a navigation id argument, and instead has a navigationId variable which it sets itself.

The fix should probably be on the HTML side, to add (back?) that argument. Otherwise, WebDriver BiDi cannot know if the callbacks its getting are due to its own command, or other things happening at the same time.

cc @jgraham