Add mandatory input and output docs to workflow

Render usage and output docs for workflow versions and check their presence when creating/updating a workflow.

Depends on clowm-workflow-service#23 (closed).

changed milestone to %Version 2.0.0

added Workflow label

assigned to @daniel.goebel

marked this issue as related to clowm-workflow-service#23 (closed)

created branch feature/49-add-mandatory-input-and-output-docs to address this issue

mentioned in merge request !42 (merged)

mentioned in commit 18b178ec

mentioned in commit e9341dae

closed with merge request !42 (merged)

mentioned in commit 79049cec