JS refactors (#22227)

- Replace all default exports with named exports, except for Vue SFCs
- Remove names from Vue SFCs, they are automatically inferred from the
filename
- Misc whitespace-related tweaks

web_src/js/features/serviceworker.js

@@ -35,7 +35,7 @@ async function checkCacheValidity() {
   }
 }
 
-export default async function initServiceWorker() {
+export async function initServiceWorker() {
   if (!('serviceWorker' in navigator)) return;
 
   if (useServiceWorker) {