Imply very_long_tail -> long_tail

BUR #15167 has been rejected.

create implication very_long_tail -> long_tail

In the same vein as very long hair.

I'm not convinced we need long tail. Most tails are long, and we have short tail for the exception.

This bulk update request is pending automatic rejection in 5 days.

This bulk update request has been rejected because it was not approved within 45 days.

The bulk update request #15167 (forum #233346) has been rejected by @DanbooruBot.