Add support for BigQuery table templates

Based on the recent [BigQuery update](https://cloud.google.com/bigquery/docs/reference/v2/tabledata/insertAll#templateSuffix) we should add support for table templates.

More in details we should provide support for the `templateSuffix` parameter in [TableData: insertAll](https://cloud.google.com/bigquery/docs/reference/v2/tabledata/insertAll#templateSuffix).
