Vite + TypeScript (#836)

Resolves #803

This is an initial commit to allow migrating to typescript bit by bit.
It introduces vite.
It removes all the webpack configuration (which I have no clue what all
the profiling are needed for, and couldn't find anything in the readme).
It also changes a single file from javascript to typescript:
`urlopen.js` -> `urlopen.ts`
Which was done manually, later on I'll see if I can automate most of the
migration.
For now, everything seems to work as expected.
I also upgrades storybook to use vite and renames the stories to jsx (I
honestly don't know why this complexity is needed here, but I'll keep it
for now).

cc: @damianstasik

vite.config.ts

@@ -0,0 +1,12 @@
+import { defineConfig } from "vite";
+import react from "@vitejs/plugin-react";
+
+export default defineConfig({
+  server: {
+    port: 8888
+  },
+  plugins: [react()],
+  define: {
+    global: "window",
+  },
+});