Item Filter for Hoppers

Add a dedicated "Filter Slot" to the hopper UI. If you place an item into this slot, the hopper will only pull and transfer that specific item, ignoring everything else. If the slot is empty, the hopper works as usual. ​Example for a Mob Farm: When resources drop from a mob farm, you can easily sort them using a chain of hoppers: ​Hopper 1 (Filter: Gunpowder): Pulls only gunpowder into the first chest. ​Hopper 2 (Filter: Rotten Flesh): Pulls only rotten flesh into the second chest. ​Hopper 3 (Filter: Bone): Pulls only bones into the third chest. ​Why it’s needed: Right now, creating an item sorter requires building large, complex redstone circuits (comparators, repeaters, torches) that take up too much space and cause server lag. Built-in hopper filters would make mob farms and storage systems compact, easy to build for everyone, and lag-free.