[node] Add streaming support for vc dev (#9745)

Until now, the user code response it's buffered and serialized. This is
mismatching how Vercel works these days.

This PR enables streaming response in `vc dev` for Edge/Serverless.

As part of the implementation, the `node-bridge` which spawns a process
to consume the user code is not necessary anymore.

Some necessary files (like HTTP server helpers) have been moved to live
in node builder package instead.

---------

Co-authored-by: Ethan Arrowood <ethan.arrowood@vercel.com>
Co-authored-by: Sean Massa <EndangeredMassa@gmail.com>

packages/node/src/serverless-functions/dynamic-import.js

@@ -0,0 +1,13 @@
+'use strict';
+
+const { pathToFileURL } = require('url');
+const { isAbsolute } = require('path');
+
+function dynamicImport(filepath) {
+  const id = isAbsolute(filepath) ? pathToFileURL(filepath).href : filepath;
+  return import(id);
+}
+
+module.exports = {
+  dynamicImport,
+};