Page URL method to accept a content representation parameter

The same way that a page URL method can receive language and Kirby params as parameters to the function, it would be convenient to be able for it to receive the content representation as well. That way, if you want to construct a URL that looks like:

mysite.com/en/home.xml/color:red

You can elegantly construct it using something like:

page('home')->url(['params' => ['color' => 'red'], 'representation' => 'xml'])