JWT based authentication

[MrChatterjee98]

Implement JWT-based authentication using Spring Security. After a successful login, the server should issue a signed JSON Web Token containing user identity and roles. Clients will include this token in the Authorization header of each request, and a custom filter will validate the token and set the authentication in the SecurityContext. The solution should be fully stateless, eliminating the need for server-side sessions and ensuring scalability for REST APIs and microservices.

[MrChatterjee98]

@Prathamesh-007 I checked your auth URLs and created this issue to improve it, if you assign it to me, I can start working on it.

[Prathamesh-007]

I was thinking about adding this issue but it seemed a bit complex for Hacktoberfest. But if you have worked with it then go ahead! Just a simple JWT Bearer token based auth will be good enough as a start!

[MrChatterjee98]

@Prathamesh-007 I created a PR for this