### 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_
from moto.sns.exceptions import DuplicateSnsEndpointError
from moto.sns.models import SNSBackend as MotoSNSBackend
from requests.models import Request, Response
from six.moves.urllib import parse as urlparse
from localstack.config import external_service_url
from localstack.constants import MOTO_ACCOUNT_ID, TEST_AWS_ACCOUNT_ID
from localstack.services.awslambda import lambda_api
from localstack.services.generic_proxy import RegionBackend
from localstack.services.install import SQS_BACKEND_IMPL
from localstack.utils.analytics import event_publisher
from localstack.utils.aws import aws_stack
from localstack.utils.aws.aws_responses import create_sqs_system_attributes, response_regex_replace
from localstack.utils.aws.dead_letter_queue import sns_error_to_dead_letter_queue
from localstack.utils.cloudwatch.cloudwatch_util import store_cloudwatch_logs
from localstack.utils.common import (
    json_safe,
    long_uid,
    md5,
    not_none_or,
    parse_request_data,
    short_uid,
    start_thread,
    timestamp_millis,
    to_bytes,
    to_str,
)
from localstack.utils.persistence import PersistingProxyListener
LOG = logging.getLogger(__name__)
HTTP_SUBSCRIPTION_ATTRIBUTES = ["UnsubscribeURL"]
class SNSBackend(RegionBackend):