feat: add current user’s username as added_who in CreateAsync method

DigitalData.UserManager.Application/Services/UserService.cs

@@ -51,6 +51,10 @@ namespace DigitalData.UserManager.Application.Services
             if (await HasEntity(user.Id))
                 return Result.Fail<int>().Message(_localizer[Key.UserAlreadyExists]);
 
+            //set the user
+            var current_user = await GetUserAsync();
+            user.AddedWho = current_user?.Username ?? "UNAUTHORIZED";
+
             var createdUser = await _repository.CreateAsync(user);
             if (createdUser is null)
                 return Result.Fail<int>();