Migrate to vite and some more stuff

- server: add a `Track` class
- server: add a create_track_class function
- client: migrate from vue-cli to vite

.eslintrc.js

@@ -1,17 +1,11 @@
 module.exports = {
   root: true,
   env: {
-    node: true
-  },
-  'extends': [
-    'plugin:vue/vue3-essential',
-    'eslint:recommended'
-  ],
-  parserOptions: {
-    parser: 'babel-eslint'
+    es2021: true,
   },
+  extends: ["plugin:vue/vue3-essential", "eslint:recommended"],
   rules: {
-    'no-console': process.env.NODE_ENV === 'production' ? 'warn' : 'off',
-    'no-debugger': process.env.NODE_ENV === 'production' ? 'warn' : 'off'
-  }
-}
+    "no-console": process.env.NODE_ENV === "production" ? "warn" : "off",
+    "no-debugger": process.env.NODE_ENV === "production" ? "warn" : "off",
+  },
+};