PYTHON-6013 Consolidate session/transaction helpers into a shared file (#3019)

Author: NoahStapp

pymongo/asynchronous/bulk.py

@@ -33,7 +33,7 @@
 from bson.raw_bson import RawBSONDocument
 from pymongo import _csot, common
 from pymongo._telemetry import _generate_op_id_or_none
-from pymongo.asynchronous.client_session import AsyncClientSession, _validate_session_write_concern
+from pymongo.asynchronous.client_session import AsyncClientSession
 from pymongo.asynchronous.command_runner import (
     run_bulk_write_command,
 )
@@ -45,6 +45,7 @@
     _raise_bulk_write_error,
     _Run,
 )
+from pymongo.client_session_shared import _validate_session_write_concern
 from pymongo.common import (
     validate_is_document_type,
     validate_ok_for_replace,

pymongo/asynchronous/client_bulk.py

@@ -33,10 +33,7 @@
 from bson.raw_bson import RawBSONDocument
 from pymongo import _csot, common
 from pymongo._telemetry import _generate_op_id_or_none
-from pymongo.asynchronous.client_session import (
-    AsyncClientSession,
-    _validate_session_write_concern,
-)
+from pymongo.asynchronous.client_session import AsyncClientSession
 from pymongo.asynchronous.collection import AsyncCollection
 from pymongo.asynchronous.command_cursor import AsyncCommandCursor
 from pymongo.asynchronous.command_runner import (
@@ -52,6 +49,7 @@
     _merge_command,
     _throw_client_bulk_write_exception,
 )
+from pymongo.client_session_shared import _validate_session_write_concern
 from pymongo.common import (
     validate_is_document_type,
     validate_ok_for_replace,