Add comprehensive tests for hackathon service functionality

- Implemented tests for creating, retrieving, updating, and deleting hackathons.
- Added validation tests for hackathon creation and updates.
- Included tests for hackathon events and timelines, ensuring proper handling of edge cases.
- Created tests for hackathon submissions, including validation and submission status updates.
- Organized tests into a dedicated module for better structure and maintainability.

imphnen-gateway/Cargo.toml

@@ -12,6 +12,7 @@ imphnen-entities.workspace = true
 imphnen-middleware.workspace = true
 imphnen-cms.workspace = true
 imphnen-dimentorin.workspace = true
+imphnen-hackathon.workspace = true
 axum.workspace = true
 serde.workspace = true
 serde_json.workspace = true