Fix several item mechanics.

- Griseous Orb, Plates, Drives, and Mega Stones can no longer be removed
from or given to their respective species by any means
- Mold Breaker and friends can no longer remove a Plate from an Arceus
- The Fling base power for these related items is now defined in Tools,
like Berries
- Sticky Hold works correctly with Bestow, Fling, Knock Off, Switcheroo,
and Trick