Add support for UrlObject

[korsvanloon]

The next/link object can have a regular object as href, but the react-transition-progress link calls toString on the href resulting in [Object object].
It needs the format function from the url library instead:

import { format } from "url";

const hrefString = typeof href === "string" ? href : format(href)

[timneutkens]

Feel free to send a PR.

[korsvanloon]

here you go :)
added in an extra fix for scroll behaviour

[korsvanloon]

@timneutkens Could you please have a look at my PR? And trigger another release?
The CMD+click fix would also be great to have released.