migrate to Manifest V3 and update scripting methods

Author: barateza

app/javascripts/browser/tabs.js

@@ -20,7 +20,10 @@ var tabs = {
   },
 
   executeScript: function(tabId, script) {
-    chrome.tabs.executeScript(tabId, { code: script });
+    chrome.scripting.executeScript({
+      target: { tabId: tabId },
+      func: new Function(script)
+    });
   }
 
 };

app/javascripts/tabWatcher.js

@@ -1 +1 @@
-require('./browser/listeners.js');
+importScripts('./browser/listeners.js');

app/manifest.json

@@ -1,27 +1,27 @@
 {
-  "manifest_version": 2,
+  "manifest_version": 3,
   "default_locale": "en",
   "update_url":"http://clients2.google.com/service/update2/crx",
   "name": "Zendesk Quicktab",
   "description": "Well behaved browser tabs for Zendesk agents",
   "version": "0.12.0",
   "background": {
-    "scripts": ["javascripts/tabWatcher.js"],
-    "persistent": true
+    "service_worker": "javascripts/tabWatcher.js"
   },
-  "page_action": {
+  "action": {
     "default_icon": {
       "19": "images/icons/icon38-enabled.png",
       "38": "images/icons/icon38-enabled.png"
     },
     "default_title": "Zendesk QuickTab",
     "default_popup": "popup.html"
-    },
+  },
   "permissions": [
     "http://*.zendesk.com/*",
     "https://*.zendesk.com/*",
     "webNavigation",
-    "tabs"
+    "tabs",
+    "scripting"
   ],
   "icons": {
     "16":   "images/icons/icon-16.png",