feat: Implement User Package Status and User Order Management features

- Added GetUserPackageStatus functionality with mapping and service implementation.
- Introduced UserOrder service methods for updating order status, applying discounts, and calculating order PV.
- Created Protobuf definitions for public messages and user orders, including necessary request and response messages.
- Implemented mapping profiles for package and user order related queries and commands.
- Developed query handlers and validators for new commands and queries in the application layer.
- Established PublicMessage service for handling public messages with appropriate gRPC endpoints.

src/BackOffice.BFF.Application/PublicMessageCQ/Queries/GetActiveMessages/GetActiveMessagesQuery.cs

@@ -0,0 +1,17 @@
+// GetActiveMessages - Public view
+using MediatR;
+
+namespace BackOffice.BFF.Application.PublicMessageCQ.Queries.GetActiveMessages;
+
+public record GetActiveMessagesQuery : IRequest<object> // TODO: define response
+{
+}
+
+public class GetActiveMessagesQueryHandler : IRequestHandler<GetActiveMessagesQuery, object>
+{
+    public async Task<object> Handle(GetActiveMessagesQuery request, CancellationToken cancellationToken)
+    {
+        // TODO: gRPC call to CMS PublicMessageContract.GetActiveMessages
+        throw new NotImplementedException();
+    }
+}