[JS] Add support for interval types in javascript

Update integration_test.py to include interval tests for JSTest once this is done.

**Reporter**: [Micah Kornfield](https://issues.apache.org/jira/browse/ARROW-5239) / @emkornfield
#### Related issues:
- [[Format] Add Timedelta type to describe time intervals](https://github.com/apache/arrow/issues/16443) (is blocked by)

_{**Note**: *This issue was originally created as [ARROW-5239](https://issues.apache.org/jira/browse/ARROW-5239). Please see the [migration documentation](https://github.com/apache/arrow/issues/14542) for further details.*}