Change Bodhisattva to a gentag

BUR #44371 has been rejected.

category bodhisattva -> general

There are multiple Bodhisattvas (Guanyin and Maitreya are examples), this is more akin to a species tag.

This tag should probably be split into specific copyrights and real life equivalents. The wiki needs to clarify what it's for, for one.

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 #44371 (forum #371979) has been rejected by @DanbooruBot.