feat add native_http_server.dart

native_http_server.dart

@@ -0,0 +1,10 @@
+// deno --unstable native_http_server.dart
+const body = new TextEncoder().encode("Hello World");
+for await (const conn of Deno.listen({ port: 4500 })) {
+  (async () => {
+    for await (const { respondWith } of Deno.serveHttp(conn)) {
+      respondWith(new Response(body));
+    }
+  })();
+}
+