[IMPLEMENTED] Notification Improvements

[AMG]

Notifications could be improved upon based on what my users have told me.

• Upon joining a group, Discussion forums should be watched automatically (with the option to unwatch, of course)
• Notification variations are sorely needed. For example, the option to not receive Reaction notifications.

Also I suppose this is an incompatibility with Alert Improvements by Xon -- Group notifs do not disappear unless manually removed with the "Mark all as read" button.

 

[Truonglv]

Now whenever user join group they will be automatically watch all forums inside the group.