* Adds integration tests for Role repository

This commit introduces integration tests for the Role repository, covering create, delete, edit, and list operations.

These tests ensure the repository functions correctly in various scenarios,
including:
- Basic CRUD operations
- Handling duplicate names (case-sensitive and case-insensitive)
- Normalization of role names
- Deleting roles with user associations
- Ordering of roles
- Handling non-existent role IDs

These tests improve the reliability and stability of the role management functionality.

* improve test readability