- Added default values for grant types, response types, application type, and token endpoint auth method during dynamic client registration.
- Implemented nil checks for client information in the CreateClient and UpdateClient methods to ensure robust error handling and validation.
- Deleted the OAuth interface and related types that were previously defined in the `interfaces.go` and `types.go` files, streamlining the codebase.
- Updated the `oauth.go` file to integrate user and client providers directly, enhancing the service's functionality and reducing complexity.
- Refactored the user information retrieval method to utilize the new user provider structure, ensuring compatibility with the updated architecture.
