Allows injection of the CMSApplication + DatabaseDriver classes into the Workflow class (this is to allow future unit testing of the class).
Cleanup constructor - the options array (and setOptions method) weren't used by the class anymore - they've been removed in the large refactor. It now just requires a string of the extension name.
Testing Instructions
Workflow related functionalities unchanged. Install sample data and create and modify workflows
Documentation Changes Required
Possibly. Not sure whether the documentation covers the constructor. It's likely it only covers using the trait.