Simple API to lock items (in inventory or in slot) for Nukkit

Just register the item you want to lock in LockedItemRegistry when enabling your plugin

LockedItemRegistry.registerLockedItem(ItemID.DIAMOND, true);

to lock item in slot ( you can't move the item in inventory but you can't drop it ).

LockedItemRegistry.registerLockedItem(ItemID.DIAMOND, false);

to lock item in inventory ( you can move the item in inventory but you can't drop it )