imply pikachu_tail -> pokemon_tail

BUR #5901 has been approved by @evazion.

remove implication pikachu_tail -> tail
create implication pikachu_tail -> pokemon_tail
create implication pokemon_tail -> tail

pikachu ears already implicates pokemon ears.

The bulk update request #5901 (forum #188828) has been approved by @evazion.

Fake tail might be more accurate here, since you wouldn't use Pikachu tail for a real tail on an actual Pikachu, only on fake tails worn by characters dressed like Pikachu.