chore(linux): Fix l10n language mappings

Also rename the .po files to match the new mappings:

- `bwr_NT.po` -> `brw_NG.po`: the language shows up as `bwr-ng` in
  Crowdin, and there's no `NT` country code.
- `ha_HG.po` -> `ha.po`: the language shows up as `ha` in Crowdin and
  there's no `HG` country code.
- `shu_latn.po` -> `shu@latin.po`: the convention seems to be to put
  the script after `@` sign.