Expose transcription metadata and worker run query params on ListElementChildren

Closes #202 (closed)

Exposes:

• transcription_worker_version
• transcription_worker_run
• with_metadata
• worker_run

arkindex_worker/worker/element.py

@@ -416,7 +416,7 @@ class ElementMixin(object):
                 )
             if worker_run is not None:
                 # If worker_run=False, filter by manual worker_run e.g. None
-                worker_run_id = worker_run if worker_run else None
+                worker_run_id = worker_run or None
                 query = query.where(CachedElement.worker_run_id == worker_run_id)
 
             return query