Use vite.js instead of react-scripts

- react-scripts are not maintained anymore
- vite.js is well suited for single page applications

See https://darekkay.com/blog/create-react-app-to-vite/

Change-Id: Ib884748e373094a640b576894ff67b98c3584ec8

src/index.jsx

@@ -1,8 +1,10 @@
 import React from "react";
-import { createRoot } from "react-dom/client";
+import ReactDOM from "react-dom/client";
 import App from "./App";
 
-createRoot(document.getElementById("root")).render(
+const REACT_APP_SERVER = import.meta.env.VITE_APP_SERVER;
+
+ReactDOM.createRoot(document.getElementById("root")).render(
   <React.StrictMode>
     <App />
   </React.StrictMode>