Allow copied code from core to use #if LOCALTEST

[ivarne]

This makes it simpler to maintain (almost) the code in multiple repositories greatly simplifying maintenance when copying changes.

        var validationResult = _validator.Validate(emailNotificationOrderRequest);
        if (!validationResult.IsValid)
        {
            validationResult.AddToModelState(this.ModelState);
             return ValidationProblem(ModelState);
         }

#if LOCALTEST
         string creator = "localtest";
#else
         string? creator = HttpContext.GetOrg();

         if (creator == null)
         {
             return Forbid();
         }
#endif

         var orderRequest = emailNotificationOrderRequest.MapToOrderRequest(creator);
         (NotificationOrder? registeredOrder, ServiceError? error) = await _orderService.RegisterEmailNotificationOrder(orderRequest);

Verification

• [ ] Your code builds clean without any errors or warnings
• [ ] Manual testing done (required)
• [ ] Relevant automated test added (if you find this hard, leave it and we'll help out)
• [ ] All tests run green

Documentation

• [ ] User documentation is updated with a separate linked PR in altinn-studio-docs. (if applicable)