gen-tarball.sh: Support local translations for all languages
* packages/gen-tarball.sh: Add local_l10n for mimetreeparser. Merge local translations for all languages for which we have such a file.
(cherry picked from commit 6c8bd6941344ef2453cfb6f689c3f0de02d29b35)
- GnuPG-bug-id: T7489