Ref. Symptoms / observations / job analysis feature

Context: This follows on to TRT-2378 which enhanced the JAQ (Job Artifact Query) dialog to allow users to save queries as symptom specifications.

That dialog enables create/update for symptoms and creating labels, but does not allow editing labels or deleting either. In the context of symptom creation from a query, it's a bit too complicated to include a full UI for that. JAQ is a good place to try out queries and turn them into symptoms, but there probably should be some kind of separate management UI for existing symptoms and labels. This would likely be complicated by any implementation of compound symptoms (with logic based on other labels) so keep that in mind.

Action Items:

• Enable authenticated users to do full CRUD on symptoms and labels with the UI. (Deletion should be "soft" so we don't leave dangling pointers to symptoms and labels just because we no longer use them. We may need to resurrect them as well.)
• Assuming this UI is outside JAQ, link to it appropriately from JAQ.