Don't label edge from Workflow InputParameter to WorkflowSteps

[mr-c]

Using the following example

https://view.commonwl.org/workflows/github.com/mr-c/scalability-reproducibility-chapter/blob/cd0cba3a2371942a5a3cb2c27c742ba38eb23477/CWL/per_cluster_workflow.cwl

The label is likely redundant (match between the WorkflowStep.id and the Workflow.InputParameter.label) or confusing (the WorkflowStep.id may be very generic).

Once common-workflow-language/common-workflow-language#541 is addressed then that WorkflowStep.label can be used to override if the Workflow.InputParameter is connected to multiple WorkflowSteps