multipart/form-data playground (#4465)

* adding toFormData test

* adding toFormData

* initial multipart-FormData playground

* formdata playground title

* Fix examples/postMultipartFormData/server.js to the examples/**/server.js format, and so event end runs.

Co-authored-by: Jay <jasonsaayman@gmail.com>

examples/postMultipartFormData/server.js

@@ -0,0 +1,13 @@
+module.exports = function (req, res) {
+  
+  req.on('data', function (chunk) {
+  });
+
+  req.on('end', function () {
+    console.log('POST  received');
+    res.writeHead(200, {
+      'Content-Type': 'text/json'
+    });
+    res.end();
+  });
+};