Add transfer checksum verification in copy module (#35367)

* Add transfer checksum verification in copy module, to ensure that the file was transferred to the remote successfully. Fixes #35029

* Guard on no checksum

* Add version_added

lib/ansible/plugins/action/copy.py

@@ -291,6 +291,9 @@ class ActionModule(ActionBase):
                     original_basename=source_rel,
                 )
             )
+            if not self._task.args.get('checksum'):
+                new_module_args['checksum'] = local_checksum
+
             if lmode:
                 new_module_args['mode'] = lmode