Stackable Potions

### Stackable Potions **Requires Fabric API** * Makes normal, splash, and lingering potions stack to 16. * Adds a 1s cooldown for throwing splash and lingering potions that have instant effects. * The cooldown is separate for splash and lingering potions as well as separate for each type of instant effect potion. ### Compatibility: * Should be safe to add/remove from existing worlds. * Functional when loaded only server-side and compatible with vanilla clients, however: * Potion cooldowns are not visible. * Brief client-side desync when stacking or moving stacked potions. ### Planned Features: * Configuration for stack size, cooldown, and cooldown length.