Check two Headers field name and field value equality.

import { equalsHeaders } from "https://deno.land/x/http_utils@$VERSION/header.ts";
import { assertEquals } from "https://deno.land/std@$VERSION/testing/asserts.ts";

assertEquals(
  equalsHeaders(new Headers({ a: "b" }), new Headers({ a: "b" })),
  true,
);
assertEquals(
  equalsHeaders(new Headers({ a: "b" }), new Headers({ c: "d" })),
  false,
);