add api message to request the currently selected item slot from a player

FactoryCraft/Player.cpp

@@ -352,6 +352,17 @@ void Player::playerApi(
             if (target) target->applyCurrentRecipie();
             break;
         }
+        case 8: // request left hand position
+        {
+            NetworkMessage* msg = new NetworkMessage();
+            msg->addressGui("gui_item_bar");
+            char* message = new char[5];
+            message[0] = 3; // set selected slot
+            *(int*)(message + 1) = leftHandPosition;
+            msg->setMessage(message, 5);
+            Game::INSTANCE->sendMessage(msg, this);
+            break;
+        }
     }
 }