[Java] Include compiled Flatbuffers sources in release artifacts

I'm seeing the flatc that's available in Maven foul up users because it depends on a version of glibc (2.14) which is too new for many enterprise Linux users. It would be better for the Arrow Java artifacts to not depend on flatc at all, if possible.

We could check the compiled sources into source control, but that seems less than ideal. Is there a clean way bundle them at packaging time?

**Reporter**: [Wes McKinney](https://issues.apache.org/jira/browse/ARROW-397) / @wesm

_{**Note**: *This issue was originally created as [ARROW-397](https://issues.apache.org/jira/browse/ARROW-397). Please see the [migration documentation](https://github.com/apache/arrow/issues/14542) for further details.*}

Commencez par examiner la documentation de migration liée dans l’issue et la configuration de packaging Maven pour les artefacts Arrow Java. Confirmez comment flatc intervient actuellement et définissez une voie au moment du packaging pour inclure les sources FlatBuffers compilées sans nécessiter flatc au moment de l’utilisation ; c’est terminé lorsque les artefacts de release ne dépendent plus de ce binaire pour ces sources.

Rédigé par le modèle d'indexation à partir du texte de l'issue.