[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.*}

首先查看 issue 中链接的迁移文档以及 Arrow Java 构件的 Maven 打包配置。确认当前 flatc 的参与方式，并定义一条在打包时包含已编译 FlatBuffers 源文件的路径，而无需在使用时要求 flatc；完成的标准是，release 构件不再为这些源文件依赖该二进制文件。

由索引模型根据 Issue 内容生成。