### 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_
try:
        float(x)
        return True
    except ValueError:
        return False
def evaluate_numeric_condition(conditions, value):
    if not is_number(value):
        return False
    for i in range(0, len(conditions), 2):
        value = float(value)
        operator = conditions[i]
        operand = float(conditions[i + 1])
        if operator == "=":
            if value != operand:
                return False
        elif operator == ">":
            if value <= operand:
                return False
        elif operator == "<":
            if value >= operand:
                return False
        elif operator == ">=":
            if value < operand:
                return False
        elif operator == "<=":
            if value > operand:
                return False
    return True
def evaluate_exists_condition(conditions, message_attributes, criteria):