Allow multiblock kitchen to be accessed as a single storage

[LindaJuffermans]

Since it really doesn't matter where food goes, in the kitchen cabinets/fridge/fruit basket/etc., it would be great if there is an option to use the full kitchen as a single storage system. That way when items are piped in or out, you don't have to connect pipes to each individual block but just to one block connected to the kitchen. Maybe add an external connection block to support this.