### 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 == "UntagResource":
                tags_to_remove = []
                req_tags = {k: v for k, v in req_data.items() if k.startswith("TagKeys.member.")}
                req_tags = req_tags.values()
                for tag in req_tags:
                    tags_to_remove.append(tag[0])
                do_untag_resource(topic_arn, tags_to_remove)
                return make_response(req_action)
            data = self._reset_account_id(data)
            return Request(data=data, headers=headers, method=method)
        return True
    @staticmethod
    def _extract_tags(topic_arn, req_data, is_create_topic_request, sns_backend):
        tags = []
        req_tags = {k: v for k, v in req_data.items() if k.startswith("Tags.member.")}
        existing_tags = sns_backend.sns_tags.get(topic_arn, None)
        
        for i in range(int(len(req_tags.keys()) / 2)):
            key = req_tags["Tags.member." + str(i + 1) + ".Key"][0]
            value = req_tags["Tags.member." + str(i + 1) + ".Value"][0]
            tag = {"Key": key, "Value": value}
            tags.append(tag)
            
            
            if is_create_topic_request and existing_tags is not None and tag not in existing_tags:
                return False
        do_tag_resource(topic_arn, tags)
        return True
    @staticmethod
    def _reset_account_id(data):