Real SQS throws `There should be at least one SendMessageBatchRequestEntry in the request. (Service: AmazonSQS; Status Code: 400; Error Code: AWS.SimpleQueueService.EmptyBatchRequest;` when there is a send batch of zero size.

This would be useful to mimic inside localstack in order to find these bugs earlier.
queue_name = 'queue-%s' % short_uid()
        queue_url = self.client.create_queue(QueueName=queue_name)['QueueUrl']
        payload = {}
        attrs = {'attr1': {'StringValue': 'val1', 'DataType': 'String'}}
        self.client.send_message(QueueUrl=queue_url, MessageBody=json.dumps(payload),
                                 MessageAttributes=attrs)
        result = self.client.receive_message(QueueUrl=queue_url, MessageAttributeNames=['All'])
        messages = result['Messages']
        self.assertEquals(messages[0]['MessageAttributes'], attrs)
        
        self.client.delete_queue(QueueUrl=queue_url)
    def test_send_message_with_invalid_string_attributes(self):
        queue_name = 'queue-%s' % short_uid()
        queue_url = self.client.create_queue(QueueName=queue_name)['QueueUrl']
        payload = {}
        
        
        attrs = {'attr1':
        {'StringValue': 'invalid characters, %s, %s, %s' % (chr(8), chr(11), chr(12)), 'DataType': 'String'}}
        with self.assertRaises(Exception):
            self.client.send_message(QueueUrl=queue_url, MessageBody=json.dumps(payload),
                                     MessageAttributes=attrs)
        
        self.client.delete_queue(QueueUrl=queue_url)
    def test_dead_letter_queue_config(self):