Recipes with tags can convert items of that tag

To reproduce

1. Place a furnace
2. /clear
3. /recipe give @p *
4. /give @p oak_log
5. /give @p birch_log 2
6. Open the furnace
7. Place the oak log in the input slot
8. Click the charcoal recipe
9. Observe that you now have 2 oak logs and 1 birch log