* remove two unused strings I identified while doing other things
* update two strings per request of @mahlzahn while avoiding a whole separate PR for this
* move 126 strings to JSON, some are remapped with a better structure
* previous migration: forgejo/forgejo!12280
Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/12718
Reviewed-by: Robert Wolff <mahlzahn@posteo.de>