Set Up Casbin RBAC Foundation with Database and Initial Policies

[avirajsingh7]

The goal of this sub-issue is to establish the foundational components for RBAC, including the database structure, policy loading mechanism, and initial Casbin integration.

Goals:

• Create the casbin_rule table to store RBAC policies.
• Implement a utility to load policies from a JSON file into the database.
• Set up the Casbin enforcer with a basic model and initial policies.
• Add initial tests to verify basic policy enforcement.
• Integrate Casbin policy loading into application startup.
• Define Roles and Permissions

[AkhileshNegi]

Closing this for now, as not a priority for sometime. Will come back to it later