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/FieldFunction.stories.jsx

@@ -0,0 +1,39 @@
+import React from 'react';
+import FieldFunction from '../src/components/FieldFunction';
+import {latest} from '@maplibre/maplibre-gl-style-spec'
+
+
+export default {
+  title: 'FieldFunction',
+  component: FieldFunction,
+};
+
+export const Basic = () => {
+  const value = {
+    "property": "rank",
+    "type": "categorical",
+    "default": "#222",
+    "stops": [
+      [
+        {"zoom": 6, "value": ""},
+        ["#777"]
+      ],
+      [
+        {"zoom": 10, "value": ""},
+        ["#444"]
+      ]
+    ]
+  };
+
+  return <div style={{width: "360px"}}>
+    <FieldFunction
+      onChange={() => {}}
+      value={value}
+      errors={[]}
+      fieldName={"Color"}
+      fieldType={"color"}
+      fieldSpec={latest['paint_fill']['fill-color']}
+    />
+  </div>
+};
+