URL#searchParams#delete removes "?"

[stevenvachon]

const {URL} = require("url");

const url = new URL("http://host/?param");
url.searchParams.delete("param");
url.href;
//-> http://host/

It should produce http://host/? according to @TimothyGu.

[TimothyGu]

I added this test case to WPT in web-platform-tests/wpt#6445. Let's fix it in Node.js after that PR is merged, since our current behavior seems to be the same as many browsers.

[TimothyGu]

The behavior was changed after #10480 (which, comically, was also filed by @stevenvachon).

[stevenvachon]

whatwg/url#336