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

stories/FieldNumber.stories.jsx

@@ -0,0 +1,41 @@
+import React from 'react';
+import {useActionState} from './helper';
+import FieldNumber from '../src/components/FieldNumber';
+import {Wrapper} from './ui';
+
+export default {
+  title: 'FieldNumber',
+  component: FieldNumber,
+};
+
+export const Basic = () => {
+  const [value, setValue] = useActionState("onChange", 1);
+
+  return (
+    <Wrapper>
+      <FieldNumber
+        label="number"
+        value={value}
+        onChange={setValue}
+      />
+    </Wrapper>
+  );
+};
+
+export const Range = () => {
+  const [value, setValue] = useActionState("onChange", 1);
+
+  return (
+    <Wrapper>
+      <FieldNumber
+        label="number"
+        value={value}
+        onChange={setValue}
+        min={1}
+        max={24}
+        allowRange={true}
+        rangeStep={1}
+      />
+    </Wrapper>
+  );
+};