[2020] Link warehouses with Sunset Harbor fish industry

Fish is its own resource and cannot be stored in warehouses. The warehouse AI simply doesn't support it and doesn't know what to do with it (so the warehouse will just be full of fish that you can't use or export).

The buildings that use fish produce generic goods, which CAN be stored in a warehouse. So if you can get a good flow of fish into fish factories, then you can have it go into warehouses after that.