feat: Implement hackathon registration module with controller, DTOs, repository, schema, and service

- Added registration_controller.rs to handle registration-related routes and logic.
- Created registration_dto.rs for data transfer objects related to registrations.
- Implemented registration_repository.rs for database interactions concerning registrations.
- Defined registration_schema.rs to represent the registration data structure.
- Developed registration_service.rs to encapsulate business logic for registrations.
- Established routes for registering, listing, updating, and checking in participants for hackathons.
- Added validation for registration requests and status updates.
- Included statistics retrieval for hackathon registrations.

imphnen-hackathon/src/v1/notifications/mod.rs

@@ -0,0 +1,7 @@
+pub mod notification_controller;
+pub mod notification_dto;
+pub mod notification_repository;
+pub mod notification_schema;
+pub mod notification_service;
+
+pub use notification_controller::notifications_router;