Add toasts to UI (#25449)

Fixes https://github.com/go-gitea/gitea/issues/24353

In some case like async success/error, it is useful to show toasts in UI.

webpack.config.js

@@ -73,6 +73,12 @@ export default {
     'eventsource.sharedworker': [
       fileURLToPath(new URL('web_src/js/features/eventsource.sharedworker.js', import.meta.url)),
     ],
+    ...(!isProduction && {
+      devtest: [
+        fileURLToPath(new URL('web_src/js/standalone/devtest.js', import.meta.url)),
+        fileURLToPath(new URL('web_src/css/standalone/devtest.css', import.meta.url)),
+      ],
+    }),
     ...themes,
   },
   devtool: false,