Fixed an issue with displaying named items.

Minor update with some useful features.

• Arrow pickup events are now monitored
• Canceled pickup events are now ignored, which should improve compatibility with other plugins
• Updated messaging APIs for modern Paper versions

PickupWatcher now uses queues to keep track of multiple simultaneous or sequential item pickups, and can even combine counts of stacks of the same item type.

Please note, this may not work 100% well if using the ACTIONBAR message location, as action bar messages can sometimes be lost if sent in quick succession.

Also updated to 1.21.7, of course.