### 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_
store_delivery_log(subscriber, False, message, message_id)
            sns_error_to_dead_letter_queue(subscriber["SubscriptionArn"], req_data, str(exc))
        return
    elif subscriber["Protocol"] in ["http", "https"]:
        msg_type = (req_data.get("Type") or ["Notification"])[0]
        try:
            message_body = create_sns_message_body(subscriber, req_data, message_id)
        except Exception:
            return
        try:
            response = requests.post(
                subscriber["Endpoint"],
                headers={
                    "Content-Type": "text/plain",
                    
                    
                    "x-amz-sns-message-type": msg_type,
                    "x-amz-sns-topic-arn": subscriber["TopicArn"],
                    "x-amz-sns-subscription-arn": subscriber["SubscriptionArn"],
                    "User-Agent": "Amazon Simple Notification Service Agent",
                },
                data=message_body,
                verify=False,
            )
            delivery = {
                "statusCode": response.status_code,
                "providerResponse": response.get_data(),
            }
            store_delivery_log(subscriber, True, message, message_id, delivery)
            response.raise_for_status()