✨ feat: add oauth2 methods and refactor client methods for model validation

- Added OAuth2 methods
- Removed the `@handle_and_munchify_response` decorator and replaced it with direct error handling in the `Client` class methods.
- Updated methods to validate request bodies using Pydantic models before sending requests.
- Changed the response handling to return raw responses instead of munchified objects.
- Updated the `Configuration` class to read `email_id` instead of `email` from the configuration file.
- Refactored the `handle_and_munchify_response` utility function to `handle_response`, simplifying error handling without munchifying responses.

Author: guptadev21