Use unique connector user for Db2 test suite

Currently, the Db2 test suite uses the same user account that is an administrator and it uses this same account to create all the ASN tables, creating the captured user tables, and the interactions with the CDC tables.

Ideally, the test suite should mirror a more realistic situation where there are two different user accounts, one used for the administrative bits and another used solely to run the connector, this way we can ideally pinpoint if there is ever any issue related to using differing users as would be expected in a real production environment.