### 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_
elif req_action == "ListTagsForResource":
                tags = do_list_tags_for_resource(topic_arn)
                content = "<Tags/>"
                if len(tags) > 0:
                    content = "<Tags>"
                    for tag in tags:
                        content += "<member>"
                        content += "<Key>%s</Key>" % tag["Key"]
                        content += "<Value>%s</Value>" % tag["Value"]
                        content += "</member>"
                    content += "</Tags>"
                return make_response(req_action, content=content)
            elif req_action == "CreateTopic":
                sns_backend = SNSBackend.get()
                topic_arn = aws_stack.sns_topic_arn(req_data["Name"][0])
                tag_resource_success = self._extract_tags(topic_arn, req_data, True, sns_backend)
                sns_backend.sns_subscriptions[topic_arn] = (
                    sns_backend.sns_subscriptions.get(topic_arn) or []
                )
                
                if not tag_resource_success:
                    return make_error(
                        code=400,
                        code_string="InvalidParameter",
                        message="Topic already exists with different tags",
                    )
            elif req_action == "TagResource":
                sns_backend = SNSBackend.get()
                self._extract_tags(topic_arn, req_data, False, sns_backend)
                return make_response(req_action)