feat: Enhance validation and permissions handling across controllers

- Added `ValidatedJson` extractor for automatic JSON validation in `events_controller.rs`, `testimonials_controller.rs`, `mentors_controller.rs`, `gacha_items_controller.rs`, and `hackathon_controller.rs`.
- Replaced manual permission checks with `require_permissions!` and `require_auth!` macros in relevant controllers to streamline permission handling.
- Introduced `sanitization` utilities in `sanitization.rs` for improved input sanitization.
- Added `permission_macros.rs` to encapsulate permission checking logic and reduce boilerplate.
- Updated dependencies in `Cargo.toml` to include `serde_json` and `validator`.
- Implemented error handling improvements in `notification_service.rs` for better response management.

imphnen-libs/src/lib.rs

@@ -27,7 +27,7 @@ pub mod services;
 pub mod surrealdb;
 
 pub use argon::{hash_password, verify_password};
-pub use axum::axum_init;
+pub use axum::{axum_init, ValidatedJson};
 pub use environment::{ENV, Env};
 pub use imphnen_entities::{
     MessageResponseDto,