The connectDPI function can now consume fields from ConnectionCreateParams.

[tusharad]

Previously, connectDPI was passing a nullPtr in place of ConnectionCreateParams, which meant there was no way to pass ConnectionCreateParams to connectDPI. This PR modifies connectDPI to accept values from AdditionalConnectionParams (the fields which are part of ConnectionCreateParams) and pass them to connectDPI.

For demonstration purposes, I have included authMode in AdditionalConnectionParams. More fields from ConnectionCreateParams can be added to AdditionalConnectionParams in the future as needed.

A design consideration arises from the fact that AdditionalConnectionParams contains fields for both ConnectionCreateParams and PoolCreateParams. Please let me know if this design approach is acceptable or if modifications are recommended. Thank you!

@apkhandkar @dmjio