Extend tdbc::odbc interface to add BCP commands for SQL Server schema builds

[sm-shaw]

Pull Requests #587 #592 have added bcp based loads for the SQL Server TPROC-C schema, significantly improving build times. Issue #593 proposes the same update for the TPROC-H schema.

Currently, this feature uses the external bcp command called via exec. It should be possible to extend the tdbc::odbc interface to add the bcp_init, bind and sendrow commands and call these directly from ODBC rather than using the external bcp command

https://learn.microsoft.com/en-us/sql/relational-databases/native-client-odbc-extensions-bulk-copy-functions/bcp-init?view=sql-server-ver16 https://learn.microsoft.com/en-us/sql/relational-databases/native-client-odbc-extensions-bulk-copy-functions/bcp-bind?view=sql-server-ver16 https://learn.microsoft.com/en-us/sql/relational-databases/native-client-odbc-extensions-bulk-copy-functions/bcp-sendrow?view=sql-server-ver16