[Fixed in 1.13] Cooked fish from villagers/creative inventory doesn't stack with furnace-cooked fish

The bug

Fish cooked in a furnace gets a nonsense damage value of 32767, rendering it unstackable with normal cooked fish. In vanilla bedrock, this means cooked fish from villagers and the creative menu.

This affects cod and salmon.

How to reproduce

1. Take one raw cod and one cooked cod from the creative menu
2. Put the raw cod in a furnace with fuel and cook it
3. When it's finished, take it out and try to stack it with the other cooked cod
   →  You can't