Implement permission mechanisam and insight page backend

[Rupeshiya]

Is your feature request related to a problem? Please describe.

1. As of now, only the creators of a particular post/event/project was allowed to perform edit or delete operation, but the admins should also have the access to perform these operations irrespective of the creator.
2. There is no backend for the insight page of the client-side to check the overview of organisation or members or search any members.

Describe the solution you'd like
Implemented backend for the above-mentioned problems:

Additional context
Working on it