Persist rejected data table

[jeremyprime]

The rejected data table is a temporary table, and due to our implementation it is never persisted to Vertica. See the documentation regarding the rejected data table and the use of COPY ... NO COMMIT here.

This ticket is to persist the rejected data table, but without affecting our current logic around committing or not committing data based on the error threshold. The rejected data should be saved whenever there is at least one rejected row, but this should not affect whether we commit or do not commit the actual data.

We should also consider adding connector options to enable this functionality and specify the table name for the rejected data.
For example, we could add a persist_rejected_data option (defaults to true) and a rejected_data_table option (defaults to <table>_<session_id>_REJECTS).

Note that we added some logging of rejected table data under #275.