Implement notification system using socket.io

[Rupeshiya]

Is your feature request related to a problem? Please describe.
As of now, there is no backend for notification system, so user of the platform would not be able to get any type of real-time notifications. Like if any event is going to be hosted by the org, or org is kept under maintenance, or user A follows user B, etc. So in all those cases, the user will not be able to get any notifications

Describe the solution you'd like
Implement backend for notifications system using socket.io and node.js and store that in db for first time page load.

Additional context
Working on it.