Supporting non-standard schemas on SQL Server and PDW

Both SQL Server and PDW have the notion of schemas in addition to databases. Until now, WhiteRabbit only supported scanning of tables in the standard ('dbo') schema, for example `my_database.dbo.person'. Attempts to scan tables in other schemas would result in an error.

This new version supports scanning tables in non-standard schemas by prefixing the table name with the schema name.