clothes_switch alias

The bulk update request #10962 has been rejected.

create alias clothes_switch -> costume_switch

Somehow, it's always the first thing I think of when trying to write costume switch.

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 #10962 (forum #215491) has been rejected by @DanbooruBot.