Use delete w/ obj store mgr create() if add fails.

Fixing ObjectStoreDatasetManager create() function so that it calls the
delete() function if initial data fails to be added (and thus the
dataset does not need to end up created); previous logic that just
removed the bucket would fail if the bucket had anything in it.

python/lib/modeldata/dmod/modeldata/data/object_store_manager.py

@@ -331,20 +331,24 @@ def create(self, name: str, category: DataCategory, domain: DataDomain, is_read_
         dataset = Dataset(name=name, category=category, data_domain=domain, dataset_type=DatasetType.OBJECT_STORE,
                           manager=self, access_location=access_loc, is_read_only=is_read_only, created_on=created_on,
                           last_updated=created_on, expires_on=expires_on)
+
+        # Once dataset is added to ``datasets``, it's "managed," so calls to add_data, delete, etc., should work
         self.datasets[name] = dataset
+
         # Put in a try block to make sure the dataset only remains if adding data worked as needed (if applicable)
         try:
             if initial_data is not None:
                 initial_data.add_initial_data()
 
+            # TODO: (later) consider whether dataset should not be deleted if everything else worked until this
             # Then updated the persisted state file and return
             self.persist_serialized(name)
+
             return dataset
-        # If we ran into any trouble writing initial data to the dataset, then bail, cleaning up the dataset from the
-        # manager and the object store itself
+        # If we ran into any trouble adding initial data, then bail, cleaning up the dataset and backing storage
         except Exception as e:
-            self.datasets.pop(name)
-            self._client.remove_bucket(name)
+            # Since the dataset is "managed," we can call delete()
+            self.delete(dataset=dataset)
             raise e
 
     @property