### 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_
except Exception as exc:
            LOG.info(
                "Received error on sending SNS message, putting to DLQ (if configured): %s" % exc
            )
            store_delivery_log(subscriber, False, message, message_id)
            sns_error_to_dead_letter_queue(subscriber["SubscriptionArn"], req_data, str(exc))
        return
    elif subscriber["Protocol"] == "application":
        try:
            sns_client = aws_stack.connect_to_service("sns")
            sns_client.publish(TargetArn=subscriber["Endpoint"], Message=message)
            store_delivery_log(subscriber, True, message, message_id)
        except Exception as exc:
            LOG.warning(
                "Unable to forward SNS message to SNS platform app: %s %s"
                % (exc, traceback.format_exc())
            )
            store_delivery_log(subscriber, False, message, message_id)
            sns_error_to_dead_letter_queue(subscriber["SubscriptionArn"], req_data, str(exc))
        return
    elif subscriber["Protocol"] == "email":
        ses_client = aws_stack.connect_to_service("ses")
        if subscriber.get("Endpoint"):
            ses_client.verify_email_address(EmailAddress=subscriber.get("Endpoint"))
            ses_client.verify_email_address(EmailAddress="admin@localstack.com")
            ses_client.send_email(
                Source="admin@localstack.com",
                Message={
                    "Body": {"Text": {"Data": message}},
                    "Subject": {"Data": "SNS-Subscriber-Endpoint"},