Use URL instead of creating an <a> tag

[philipwalton]

All browsers that support modules also support the URL API, so I don't see any reason to use the <a> tag just to convert a relative URL to an absolute one.

Your toAbsoluteURL() function could be removed and you could update the usage as follows:

- const absURL = toAbsoluteURL(url);
+ const absURL = new URL(url, location).href;