[Ruby] Add API to read/write by partitions

We should add convenient API for `Arrow::Table#save`/`Arrow::Table.load to allow read or write multiple files at once`

**Reporter**: [Kanstantsin Ilchanka](https://issues.apache.org/jira/browse/ARROW-14604) / @simpl1g
**Assignee**: [Kouhei Sutou](https://issues.apache.org/jira/browse/ARROW-14604) / @kou

_{**Note**: *This issue was originally created as [ARROW-14604](https://issues.apache.org/jira/browse/ARROW-14604). Please see the [migration documentation](https://github.com/apache/arrow/issues/14542) for further details.*}