Lace-trimmed_thighhighs to imply lace-trimmed_legwear

BUR #370 has been rejected.

create implication lace-trimmed_thighhighs -> lace-trimmed_legwear

Pretty self-explanatory.

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 #370 (forum #2517) has been rejected by @DanbooruBot.

I'm not sure we need both of these. Other legwear tags were split out into socks, thighhighs, pantyhose etc.