Fix CDN detection and update app icon

Remove 'type: module' from manifest.json background scripts.
ES modules have isolated scope, preventing constants.js variables
from being accessible in background.js. Classic scripts share
global scope, which is what we need.

Also update app icon to new design with cloud and HIT badge.

Author: bartTC

CF Cache Status/CF Cache Status Extension/Resources/images/app-icon-128.png

@@ -19,8 +19,7 @@
     }
   },
   "background": {
-    "scripts": ["constants.js", "background.js"],
-    "type": "module"
+    "scripts": ["constants.js", "background.js"]
   },
   "content_scripts": [
     {