### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

When you publish a message to SNS without a *body* (e.g. only attributes) it succeeds.

### Expected Behavior

Trying to publish a message without a *body* should fail (at least it does when trying to do this in AWS)

### How are you starting LocalStack?

Custom (please describe below)

### Steps To Reproduce

#### How are you starting localstack (e.g., `bin/localstack` command, arguments, or `docker-compose.yml`)

using Java testcontainers...

#### Client commands (e.g., AWS SDK code snippet, or sequence of "awslocal" commands)

```bash
#!/bin/sh
 
queue_arn=$(awslocal sqs create-queue --queue-name $QUEUE_NAME --output text)
echo "Queue ARN: $queue_arn"

topic_arn=$(awslocal sns create-topic --name $TOPIC_NAME --output text)
echo "Topic ARN: $topic_arn"

subscription_arn=$(awslocal sns subscribe \
    --attributes RawMessageDelivery=true \
    --topic-arn "$topic_arn" \
    --protocol sqs \
    --notification-endpoint "$queue_arn" \
    --output text)
echo "Subscription ARN: $subscription_arn" 
```


### Environment

```markdown
- OS: OSX 11.5.2
- LocalStack: 0.13.0
- Docker Desktop: v20.10.8
```


### Anything else?

_No response_
sms_messages = sns_backend.sms_messages
            for contact in list_of_contacts:
                sms_was_found = False
                for message in sms_messages:
                    if message["endpoint"] == contact:
                        sms_was_found = True
                        break
                self.assertTrue(sms_was_found)
        retry(check_messages, sleep=0.5)
    def test_publish_sqs_from_sns(self):
        topic = self.sns_client.create_topic(Name="test_topic3")
        topic_arn = topic["TopicArn"]
        test_queue = self.sqs_client.create_queue(QueueName="test_queue3")
        queue_url = test_queue["QueueUrl"]
        subscription_arn = self.sns_client.subscribe(
            TopicArn=topic_arn,
            Protocol="sqs",
            Endpoint=queue_url,
            Attributes={"RawMessageDelivery": "true"},
        )["SubscriptionArn"]
        self.sns_client.publish(
            TargetArn=topic_arn,
            Message="Test msg",
            MessageAttributes={"attr1": {"DataType": "Number", "StringValue": "99.12"}},
        )
        def get_message_with_attributes(queue_url):