Provide a mechanism to choose columns of the shipment csv file

As a system administrator/implementor, I would like to be able to set the specification for the shipment file including type of file (text file), file format (CSV), content of files (fields,), (data types, expected values). This can be similar to how we are using order_file_columns and order_file_templates.

Acceptance Criteria

• A mechanism is developed to define shipment file columns and shipment file template
• File shipment file configuration can be defined by a developer (without any UI)