Refactor authentication handling and API client integration
- Updated UserProfileAvatar to use 'access_token' instead of 'ca_token' for logout.
- Removed SSEProvider from Contexts and adjusted related imports.
- Introduced useAuth hook for centralized authentication logic, including login, logout, and token management.
- Refactored useSSE to utilize the new useAuth hook for token validation.
- Updated UserQueries to check for token validity using the new method.
- Deleted AuthenticationService as its functionality is now handled by useAuth.
- Created a new ApiClient utility for handling API requests and token management.
- Updated various components and views to use the new ApiClient for API interactions.
- Removed TokenManager and migrated its functionality to the new ApiClient.
- Adjusted LoginView and related components to utilize the new authentication flow.
- Cleaned up unused variables and improved code consistency across components.
