Add <all_urls> in permissions

We already have full access to all sites via our content script so this permission doesn't add anything new but we need it to be able to establish page connection via tabs.executeScript when the extension is installed, reloaded, re-enabled.

<all_urls> also allows file:// URLs unlike *://*/* used previously. Of course it requires the corresponding checkbox being enabled on chrome://extensions page.

manifest.json

@@ -15,7 +15,8 @@
     "tabs",
     "webNavigation",
     "contextMenus",
-    "storage"
+    "storage",
+    "<all_urls>"
   ],
   "background": {
     "scripts": ["messaging.js", "storage.js", "prefs.js", "background.js", "update.js"]