Refactor messaging system to utilize LiteCqrs library

- Replaced instances of the previous messaging system with LiteCqrs across various application components, enhancing the CQRS implementation.
- Updated dependency injection to register LiteCqrs services and behaviors, streamlining command and query handling.
- Adjusted multiple command and query handlers to align with the new messaging framework, ensuring consistent functionality and improved maintainability.
- Added LiteCqrs package reference in the project file for better dependency management.

backend/tests/PnvPanel.Application.Tests/Common/Behaviors/RequireActivationBehaviorTests.cs

@@ -2,7 +2,7 @@ using NSubstitute;
 using PnvPanel.Application.Auth;
 using PnvPanel.Application.Common.Behaviors;
 using PnvPanel.Application.Common.Interfaces;
-using PnvPanel.Application.Common.Messaging;
+using LiteCqrs;
 using PnvPanel.Application.Common.Models;
 using Xunit;