Notification Stacking

[kartikarora]

Stack notifications together as one if there are more than one notifications.

[rohanagarwal94]

@kartikarora wanted to solve this. So, you want to replace the notification if any with the new one instead of generating multiple notifications?

[kartikarora]

@rohanagarwal94 Whatever approach seems good to you! Implement and send in a PR, I'll have a look!

But if there are multiple notifications, the stacked/single shown notification should say that.