Fix serviceworker output file and misc improvements (#11562)

* Fix serviceworker output file and misc improvements

- Fix output file location for production build
- Cache more asset types: fonts and worker variants
- Parallelize a few tasks during initalization
- Only invalidate caches starting with our prefix
- Remove public/serviceworker.js before building
- Remove font preloads, they cause strange cors issues
- Misc eslint config adjustments

* remove webpack output files on watch-frontend

web_src/js/index.js

@@ -2469,7 +2469,7 @@ $(document).ready(async () => {
     }
   });
 
-  // parallel init of lazy-loaded features
+  // parallel init of async loaded features
   await Promise.all([
     highlight(document.querySelectorAll('pre code')),
     attachTribute(document.querySelectorAll('#content, .emoji-input')),