Add validation to prevent duplicate national codes in user updates

src/CMSMicroservice.Application/UserCQ/Commands/UpdateUser/UpdateUserCommandHandler.cs

@@ -13,6 +13,10 @@ public class UpdateUserCommandHandler : IRequestHandler<UpdateUserCommand, Unit>
     {
         var entity = await _context.Users
             .FirstOrDefaultAsync(x => x.Id == request.Id, cancellationToken) ?? throw new NotFoundException(nameof(User), request.Id);
+        if (entity.NationalCode == request.NationalCode)
+        {
+            throw new Exception("کد ملی تکراری است");
+        }
         request.Adapt(entity);
         _context.Users.Update(entity);
         entity.AddDomainEvent(new UpdateUserEvent(entity));