Insights should be generated after workflow workers completion

Current situation

It is not unusual that with local orchestrator and java plugins deployment, for a first workflow launched after orchestrator and plugins restart, testResults notifications are not cached because they arrive at the very end of workflow, after WorklowCompleted event, and insights using these notifications cannot be generated.

Desired outcome

The issue is most possibly related to the interpeter plugin warmup, but it should be nevertheless interesting to wait for workflow workers completion before generating insights to be sure to have testResults notifications in the observer cache. So it is more a tweak to prevent possible issues.