Issue #2886567 by timmillwood, Sam152, Manuel Garcia, Vj, xjm, tstoeckler: Adding a workflow state or transition with an integer ID results in unrecoverable fatal errors

Issue #2896722 by Sam152, Wim Leers, tim.plunkett, larowlan, timmillwood: Leverage PluginWithFormsInterface to encapsulate @WorkflowType schema and clean up state/transition form methods