**Backport of forgejo/forgejo#7422**
- Add new translations, if an existing one couldn't be used.
- Use existing translations, if one existed and fit the purpose.
- Spotted by the lint-locale-usage tooling by @fogti.
(cherry picked from commit bd9366e7fc)
Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/7430
Reviewed-by: 0ko <0ko@noreply.codeberg.org>
Co-authored-by: Gusted <postmaster@gusted.xyz>
Co-committed-by: Gusted <postmaster@gusted.xyz>
49625aac60