Bulk import not accounting for identifierFieldName in import def

[jnorton2]

We need identifierFieldName in the import definition.
bulk.py create_def() should account for this. This could be done with an extra variable in the create_def() method.

API Reference : https://docs.oracle.com/cloud/latest/marketingcs_gs/OMCAC/op-api-bulk-2.0-customObjects-%7BparentId%7D-imports-post.html

[jnorton2]

You can get the same result by requiring the options to be set using the add_option(). However, it is required in every import.