The _shardsvrRenameCollection command and the rename coordinator don't seem to explicitly check for bucket namespaces.

Purpose of this ticket is to double check if it's fine for the user to directly invoke rename operations on bucket namespaces or if we should rather disallow it, always requiring to invoke rename on the view in case of timeseries.

At first glance, it should not be problematic to directly address the bucket namespace because the DDL locks are acquired on the right namespace and the coordinator works on the right namespace as well (since the translation should be a no-op).