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/emoji.js

@@ -1,7 +1,6 @@
 import emojis from '../../../assets/emoji.json';
 
-const {assetUrlPrefix} = window.config;
-const {customEmojis} = window.config;
+const {assetUrlPrefix, customEmojis} = window.config;
 
 const tempMap = {...customEmojis};
 for (const {emoji, aliases} of emojis) {