If the sftp fails, roll over to scp by default. This saves users
from having to know about the scp_if_ssh method when sftp is broken
on the remote host.
We couldn't copy to_unicode, to_bytes, to_str into module_utils because
of licensing. So once created it we had two sets of functions that did
the same things but had different implementations. To remedy that, this
change removes the ansible.utils.unicode versions of those functions.
