XCOMMONS-811: Add support for recording the extension history

* When an interactive sub-job asks a question, the parent job should update its state accordingly (WAITING) because the user interacts with the parent job. For this, the sub-job status needs to keep a reference to the parent job status (not just a flag that says it is a sub-job, like now).
* Make the ReplayJob a GroupedJob and use the same group path as extension jobs: use 'extension/namespace' if the replay targets a single namespace, and 'extension' if the replay targets multiple namespaces or the global namespace. This way a replay job that targets a single wiki will block the extension jobs on that wiki only.