Fix contributor name-related inconsistencies in release-12.sgml

Hello,

While translating Release Notes for version 12 I found some
inconsistencies with contributor names.
1. Constantine Kuznetsov and Konstantin Kuznetsov are the same person.
2. Sho Kato and Kato Sho too.
3. Takayuki Tsunakawa is present in the Acknowledgments, but Tsunakawa
Takayuki is referred in the change list.
Regarding Japanese names I found that in the Postgres documentation the
given name is mostly specified first. E.g.: Daisuke Higuchi, Haruka
Takatsuka, Hayato Kuroda, Hironobu Suzuki, Keiichi Hirobe, Kenji Uno,...
So I would remove "Kato Sho" because "Sho" is a given name:
https://en.wikipedia.org/wiki/Sh%C5%8D_(given_name)
And change "Tsunakawa Takayuki" to "Takayuki Tsunakawa" because
"Takayuki" is a given name: https://en.wikipedia.org/wiki/Takayuki

Also, there are other names spelled in the reverse order:
Fujii Masao
Koizumi Satoru
Matsumura Ryo
So I propose a second patch to fix these names too.

Best regards,
Alexander