[PLT-1489] Removed get stream and corresponding classes (#1839)

Author: Gabefire

libs/labelbox/src/labelbox/__init__.py

@@ -26,11 +26,7 @@
 from labelbox.schema.export_task import (
     BufferedJsonConverterOutput,
     ExportTask,
-    FileConverter,
-    FileConverterOutput,
-    JsonConverter,
-    JsonConverterOutput,
-    StreamType,
+    BufferedJsonConverterOutput,
 )
 from labelbox.schema.iam_integration import IAMIntegration
 from labelbox.schema.identifiable import GlobalKey, UniqueId