Beam SQL should support BigQuery in DIRECT_READ mode

SQL currently only supports reading from BigQuery in DEFAULT (EXPORT) mode. We also need to support DIRECT_READ mode. The method should be configurable by TBLPROPERTIES through the SQL CLI. This will enable us to take advantage of the DIRECT_READ features for filter and project push down.

References:

https://beam.apache.org/documentation/io/built-in/google-bigquery/#storage-api

https://beam.apache.org/blog/2019/06/04/adding-data-sources-to-sql.html

https://github.com/apache/beam/blob/c2f0d282337f3ae0196a7717712396a5a41fdde1/sdks/java/extensions/sql/src/main/java/org/apache/beam/sdk/extensions/sql/meta/provider/bigquery/BigQueryTable.java