Deprecate colored_contact_lens

BUR #18621 has been approved by @nonamethanks.

deprecate colored_contact_lenses

Viewers cannot simply determine if a character is wearing contact lenses which are responsible for their distinct eye colours or not. If their eye colours are different than what usually appears by design, there's already (official) alternate eye color for that. This seems like a pointless tag so far.
Despite being a small tag, I don't think manually nuking it before mod decision is a desirable option.

For the object, I think contact lens is enough.

This tag has cosplay_photo images like post #2761598 which isn't an off-topic tag and in this situation not ambiguous. I'm going to hazard a guess and say it's probably undertagged. I have no interest in cosplay so I don't know if this is worth tagging in addition/instead of contact lens but I don't think it warrants the wiki being changed to ambiguous without discussion.

I don't think having the tag on cosplay photos is useful, having the appropriate color_eyes tag seems enough.

There are drawn images of colored contacts being used, such as post #6228465 and post #5229887 where colored contacts are clearly being inserted.

The bulk update request #18621 (forum #248905) has been approved by @nonamethanks.

I've cleaned up contact lens a bit and removed it from cases where there wasn't any hint of their presences.

I don't think this tag was useful, the tag contact lens itself has less than three default pages of results, and it's impossible to tell even from photos whether they're really contact lenses or just photoshopped eye color.