explicit concourse job failure when terraform plan exhibits discrepancy

[poblin-orange]

Expected behavior

As an operator, i need some visual way to see the terraform plan show differences, and apply must be done

Observed behavior

When terraform plan is launched, box is just green, waiting for an apply.
Suggest adding a down stream new job, errorring if result of plan is show discrepancies (thus indicating an apply must be manually triggered).

Affected release

Reproduced on version x.y

Traces and logs