Rework the worker due to `Dataset` API changes

Closes #14 (closed), #16 (closed)

worker_generic_training_dataset/worker.py

@@ -425,7 +425,7 @@ class DatasetExtractor(DatasetWorker):
                 with contextlib.suppress(Exception):
                     self.update_dataset_state(dataset, DatasetState.Error)
 
-        message = f'Ran on {count} dataset{"s"[:count>1]}: {count - failed} completed, {failed} failed'
+        message = f'Ran on {count} dataset{"s"[:count > 1]}: {count - failed} completed, {failed} failed'
         if failed:
             logger.error(message)
             if failed >= count:  # Everything failed!