Create a debug view for an object's Workflow

[jeremyf]

In Sipity we have a debug page that allows users to see the state of the Sipity workflow:

• An object's Sipity::Workflow
• An object's Sipity::WorkflowState
• The list of Sipity::Roles that are assigned to the object, and how agents are associated with those roles (i.e. at the Workflow level or the Sipity::Entity level)

Example https://github.com/ndlib/sipity/blob/master/artifacts/for-sufia/sipity-ETD-Debug-page.png

[randalldfloyd]

The screen capture above was generated from 'debug' presenters and actors and a Curly template. The best way to navigate all of the working pieces is to view the initial commit introducing debug to Sipity: ndlib/sipity@cfe6204

The specs on that commit are helpful in understanding how the delegations and decorators work to produce what the main debug_presenter needs to populate the template.

[mjgiarlo]

Is this related to #1030 in any way, @jeremyf?