Optionally reset tasks when no jobs for participant left (looping)

[smathot]

There should be an option in the UI (a checkbox) indicating that tasks should be looped. When enabled, when the monkey finishes the last task (which would normally be the moment that you’d get a NoJobsForParticipant error) everything is reset so that the monkey starts with the first task again. No information is preserved, except the number of times that this has happened for this particular monkey.

[BmBaczkowski]

3ceda18 proposes an implementation. It adds UI on study page -> edit to enable repeatable workflow (see gif).

When all jobs of a participant are finished and a request for a next job comes, then the system checks whether looping is enabled and resets all jobs to pending (lazily triggered by API, no background process), and the jobs are repeated.

The commit makes changes to migration + schema, study model and job results JSON (adds variable to track the count of looping). I did some testing by manually manipulating DB, but I am not sure if there are some downstream effects of this on the codebase.

[smathot]

The UI implementation looks very good. But for me it doesn't work. I still get a NoJobsForParticipant error in the client. Can you add a unit test, and once that checks out explain how I can test it in the client?