Item Acceptor Blocks don't respect SidedInventories when inserting items

[myriantics]

When inserting an item stack into an inventory, Item Acceptor blocks always choose the first available slot in the whole inventory, disregarding the slots that it may have declared available for the insertion side.

Steps to reproduce:

• Place Item Acceptor and set it to input into the side of a furnace
• Right click a compatible item onto it

Expected Behavior:

• Item goes into the fuel slot

Result:

• Item goes into the ingredient slot

Potential Fix:

• Add a instanceof check for SidedInventories, which polls the getAvailableSlots() or canInsert() methods when attempting to insert an item

Relevant method:

glowcase/src/main/java/dev/hephaestus/glowcase/block/ItemAcceptorBlock.java

Line 122 in b7ae204

private ItemStack addToFirstFreeSlot(Inventory inventory, ItemStack stack) {

[TropheusJ]

this should not even be using Inventory, this should be using the transfer API