fix: import whatwg-url in a way compatible with ESM Node

src/request.js

@@ -9,7 +9,7 @@
 
 import Url from 'url';
 import Stream from 'stream';
-import {URL} from 'whatwg-url';
+import whatwgUrl from 'whatwg-url';
 import Headers, { exportNodeCompatibleHeaders } from './headers.js';
 import Body, { clone, extractContentType, getTotalBytes } from './body';
 
@@ -33,7 +33,7 @@ function parseURL(urlStr) {
 		Absolute URL: https://tools.ietf.org/html/rfc3986#section-4.3
 	*/
 	if (/^[a-zA-Z][a-zA-Z\d+\-.]*:/.exec(urlStr)) {
-		const url = new URL(urlStr);
+		const url = new whatwgUrl.URL(urlStr);
 
 		return {
 			path: url.pathname,

test/test.js

@@ -9,7 +9,7 @@ import resumer from 'resumer';
 import FormData from 'form-data';
 import stringToArrayBuffer from 'string-to-arraybuffer';
 import URLSearchParams_Polyfill from '@ungap/url-search-params';
-import { URL } from 'whatwg-url';
+import whatwgUrl from 'whatwg-url';
 import { AbortController } from 'abortcontroller-polyfill/dist/abortcontroller';
 import AbortController2 from 'abort-controller';
 
@@ -1812,7 +1812,7 @@ describe('node-fetch', () => {
 
 	it('should support fetch with WHATWG URL object', function() {
 		const url = `${base}hello`;
-		const urlObj = new URL(url);
+		const urlObj = new whatwgUrl.URL(url);
 		const req = new Request(urlObj);
 		return fetch(req).then(res => {
 			expect(res.url).to.equal(url);