## What changes were proposed in this pull request?

SparkSQL can now read from a database table with column type [TIMESTAMP WITH TIME ZONE](https://docs.oracle.com/javase/8/docs/api/java/sql/Types.html#TIMESTAMP_WITH_TIMEZONE).

## How was this patch tested?

Tested against Oracle database.

JoshRosen, you seem to know the class, would you look at this? Thanks!

Author: Jannik Arndt <jannik@jannikarndt.de>

Closes #17832 from JannikArndt/spark-20557-timestamp-with-timezone.