OIS Attribute Pass Through (Ad Hoc Attributes)

Add a capability for arbitrary Organizational Identity Source attributes to "pass through" the CoPersonRole record to downstream provisioners. These attributes might not be processed by Registry at all (other than the OIS plugin normalizing them to key/value pairs), or something like a Pipeline Plugin could be used to intercept them and place the attributes into a plugin-based data model extension.

Attributes would be made available to Provisioner Plugins, which can decide what to do with them.