### 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_
topic_name = "test-%s" % short_uid()
        tags = [{"Key": "a", "Value": "1"}, {"Key": "b", "Value": "2"}]
        kwargs = [
            {"Tags": tags},  # t
            {"Tags": tags},  # t
            {"Tags": [tags[0]]},  # t
            {"Tags": []},  # t
        ]
        responses = []
        for arg in kwargs:
            responses.append(self.sns_client.create_topic(Name=topic_name, **arg))
        # a
        for i in range(len(responses)):
            self.assertIn("TopicArn", responses[i])
        # c
        self.sns_client.delete_topic(TopicArn=responses[0]["TopicArn"])
    def test_create_platform_endpoint_check_idempotentness(self):