Optional export of external plugin data when receiving all kitchen orders

In API V9Preview1, an optional parameter includeExternalData has been added to the method [GetKitchenOrders] (https://syrve.github.io/front.api.sdk/v9/html/M_Resto_Front_Api_IOperationService_GetKitchenOrders.htm), allowing external plugin data to be loaded when receiving kitchen orders.

If the parameter includeExternalData is set to true, all kitchen orders with the [IKitchenOrder.ExternalData] field filled in will be returned. (https://syrve.github.io/front.api.sdk/v9/html/P_Resto_Front_Api_Data_Kitchen_IKitchenOrder_ExternalData.htm) — all external data from all plugins.

If external plugin data was not requested when receiving all kitchen orders, it can always be obtained for a specific kitchen order using the method [TryGetKitchenOrderExternalDataByKey] (https://syrve.github.io/front.api.sdk/v9/html/M_Resto_Front_Api_IOperationService_TryGetKitchenOrderExternalDataByKey.htm) .