[SQL] [SPARK-3236] Reading Parquet tables from Metastore mangles location

Currently we do `relation.hiveQlTable.getDataLocation.getPath`, which returns the path-part of the URI (e.g., "s3n://my-bucket/my-path" => "/my-path"). We should do `relation.hiveQlTable.getDataLocation.toString` instead, as a URI's toString returns a faithful representation of the full URI, which can later be passed into a Hadoop Path.

Author: Aaron Davidson <aaron@databricks.com>

Closes #2150 from aarondav/parquet-location and squashes the following commits:

459f72c [Aaron Davidson] [SQL] [SPARK-3236] Reading Parquet tables from Metastore mangles location