WorkRequestDetailView output tab: improve for work requests that are workflows

The WorkRequestDetailView output tab lists the "Output artifacts" and "Output data".

For a work request that is a (sub-)workflow it always shows:

Output artifacts

No artifacts produced. Output data

No output data.

It should show something more useful for the user.

Might help #919

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information