Remove require('url') in favor of URL

[feross]

(Once we're ready to drop Node 8 support)

For: brave/brave-browser#5490

[gillesdemey]

It doesn't seem viable without support for relative URLs.

Relative URLs are currently used for the redirect logic and parsed from the Location header so we will have to wait for nodejs/node#28482 to land but it requires Node 12.x — which is likely a leap too far.

nodejs/node#12682
whatwg/url#421

[feross]

It's possible to do new URL('...', 'http://example.com') to parse a relative URL.