Append _(nonsexual) to forced

BUR #16359 has been rejected.

create alias forced -> forced_(nonsexual)

Following the tied_up_(nonsexual) change, I think forced needs a similar change. More than a third of the tag was rape pictures mistagged with a large portion of them tagged forced instead of rape. There's a similar issue with molestation, with many images lacking the proper tag.

The tag needs to be cleaned up first, there's only a handful of posts under forced rating:g.

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 #16359 (forum #239277) has been rejected by @DanbooruBot.