Filter process list on "supervisor" flag instead "requesting_container_uuid"
User has a "launcher" program which manages their analysis process and submits a bunch of per-sample workflows which are all owned by the launcher.
In the current UI, this makes them "intermediate steps" but from the user's perspective, they are interested in the sample-level workflows. It is especially confusing because if they run the launcher somewhere else (not in an Arvados container), they see the individual samples at the top level, but if they do run it in an Arvados container, the sample workflows are owned by the launcher container, so they are not displayed as top level workflows.
We should consider having Workbench 2 use the "supervisor" flag to differentiate between umbrella workflows and intermediate steps.
The only issue I see is that we would need to query on both (requesting_container_uuid=null or scheduling_parameters.supervisor=true) to properly display containers run before the 2.6 release, but we don't presently support OR clauses.