Bugfix: Force close node server upon finishing response

[mina-asham]

• Relying on clients using the connection close header to close the connection leaves room for client bugs where the server can just hang until the timeout passes, this force clauses the connection completely from the server side but after flushing all the response data
• Follow up to: Bug: NodeCallbackServer Doesn't Display Sucsess/Error Pages #25
• Fixes: Bugfix: NodeCallbackServer not shutting down #35

Testing

1. Added this sample script: examples/demo-node.js

import { getAuthCode } from "../dist/index.js";

const result = await getAuthCode({
  authorizationUrl: "https://github.com",
  port: 1234,
  openBrowser: true,
  timeout: 5 * 60 * 1000, // 5 minutes
});

console.log(result);

2. Used this to run: npm run build && node examples/demo-node.js
3. Opened this page manually: http://localhost:1234/callback?code=123&status=456

[mina-asham]

@koistya any chance you can review this soon? 🙏