Add 'utils' module export (#410)

Export core utils and assets used by RWP in /utils.
Add serviceWorkerActivated() utility promise.

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Co-authored-by: emma <hi@emma.cafe>

webpack.config.js

@@ -98,6 +98,7 @@ const libConfig = (env, argv) => {
   /** @type {import('webpack').Configuration['entry']} */
   const entry = {
     index: "./src/index.ts",
+    utils: "./src/utils/index.ts",
   };
 
   const extraPlugins = [];