Implement backend for pagination, follow/unfollow, block/unblock, events by a user, posts by a user

**Is your feature request related to a problem? Please describe.**
As of now, there is no backend implementation for the functionalities like:
1. Follow or unfollow any user
2. Block or unblock user by admins
3. Get all the events created by a user
4. Get all the posts created by a user
5. Paginate all the REST API where the response of that request would be large enough to slow the system.
6. Get all the details of a user profile

**Describe the solution you'd like**
Implement REST API for all the above-mentioned functionalities.

**Additional context**
Working on it