List clients conforming to a givent query.

def SearchClients(query=None, context=None):
  """List clients conforming to a givent query."""

  args = client_pb2.ApiSearchClientsArgs(query=query)

  items = context.SendIteratorRequest("SearchClients", args)
  return utils.MapItemsIterator(lambda data: Client(data=data, context=context),
                                items)