Use labels for any workflow instructions

Current Situation

• The Controller requires use of labels to identify the position of a job in a workflow in case of multiple occurrences of the same job.

Desired Behavior

• Any workflow instructions should be assigned a label which is a unique identifier in a workflow.
• The label is reported with state transition events by the Controller.
• The label can be used with API requests to the Controller instead of specifying an order's position.