Rename hiyori_uwamura -> hiwamura_hiyori

BUR #29957 has been rejected.

rename hiyori_uwamura -> hiwamura_hiyori

Consistency with Japanese/Asian naming convention. Also, I can't exactly verify by myself if it's "Hiwamura" and not "Uwamura" from "鶸村 ひより" but it's how it goes in MyAnimeList.

The bulk update request #29957 (forum #298285) has been rejected by @staxu.

BUR #29961 has been approved by @nonamethanks.

rename hiyori_uwamura -> hiwamura_hiyori

Restarting this BUR, since it is correct according to Wikipedia, at least.

鶸村 ひより（ひわむら ひより）

The bulk update request #29961 (forum #298296) has been approved by @nonamethanks.