[Java] Optimize bit operations performance

From @animeshtrivedi's benchmark finding:

2) Materialize values from Validity and Value direct buffers instead of
calling getInt() function on the IntVector. This is implemented as a new
Unsafe reader type (

)

3) Optimize bitmap operation to check if a bit is set or not (

)

**Reporter**: [Li Jin](https://issues.apache.org/jira/browse/ARROW-3495) / @icexelloss
#### Subtasks:
- [X] [[Java] Remove Long.bitCount with simple bitmap operations](https://github.com/apache/arrow/issues/20485)
#### PRs and other links:
- [GitHub Pull Request apache/arrow#5930](https://github.com/apache/arrow/pull/5930)

_{**Note**: *This issue was originally created as [ARROW-3495](https://issues.apache.org/jira/browse/ARROW-3495). Please see the [migration documentation](https://github.com/apache/arrow/issues/14542) for further details.*}

从 benchmark 中对 ArrowReaderUnsafe.java 的引用开始，检查 Apache Arrow PR #5930，然后查看已完成的位图操作子任务，以确定还剩下什么。将请求的直接缓冲区物化和位图检查与现有的 Java 实现进行比较；完成的标准是实现剩余的优化，并验证其性能影响。

由索引模型根据 Issue 内容生成。