Workflow step integration extensions

[leoschwarz]

The workflowstep integration currently creates the workflow step referenced by ID from the template for a successful workunit.

Several thoughts/improvements are possible:

1. Reference the template only by URL and not ID so it's unambiguous among B-Fabric instances.
2. Manage this in B-Fabric instead, e.g. allowing the user to specify whether workflowstep should be created or customise it already when launching the app.
3. Automatically link samples with the workflow step.

[leoschwarz]

There is also an alternative way which would be that the workflowstep is shown when creating the workunit in a drop down. I think this will need some more consideration.

[leoschwarz]

There has been an additional request to automatically link the samples which were processed. This would actually constitute a bigger change because at the relevant level, the app runner currently does not handle sample instances.