App: Fix bug related to notifications settings

When the app loads the user notification preference from storage, it
doesn't take into account whether permission has been given to the
browser.

Hence when the user allows notification in the app settings & block
notifications in the browser setting, the notification toggle switch
in the settings view would enter a weird state where it's set to true
+ disabled (should be set to false + disabledin such a scenario).

src/App.vue

@@ -82,8 +82,7 @@ export default {
       // app Settings
       workDuration: 1500,
       breakDuration: 300,
-      // allowNotification: true && !notifications.isBlocked(),
-      allowNotification: true,
+      allowNotification: true && !notifications.isBlocked(),
       // worker objects for our timer
       timerWorker: null,
       alarmWorker: null,
@@ -217,7 +216,7 @@ export default {
           const { workDuration, breakDuration, allowNotification } = userSettings;
           this.workDuration = workDuration;
           this.breakDuration = breakDuration;
-          this.allowNotification = allowNotification;
+          this.allowNotification = allowNotification && !notifications.isBlocked();
 
           // Update `timeRemaining` to newly loaded `workDuration`
           this.timeRemaining = workDuration;