Include field in agent that states whether brief was autogenerated

[rich-iannone]

When a validation step is added to the agent object, the expectation text (the brief, a name I’d love to change in the future) is by default added immediately for the step in the lang of the agent (default is English). It would be good to know whether the text has been autogenerated or not. One reason is that when creating agent YAML, it’s not necessary to add the brief text if it’s just default text (only if it’s custom text). The same goes for taking YAML and re-creating the expressions to obtain an agent object.