### Is there an existing issue for this?

- [X] I have searched the existing issues

### Feature description

I would like to request extending `sns_listener` with an ability to understand `email-json` next to `email` protocol.

### 🧑‍💻 Implementation

1. check if protocol is `email` or `email-json`
2. for email json interpret body/message as json

### Anything else?

_No response_
req_data,
    headers,
    subscription_arn,
    skip_checks,
    sns_backend,
    subscriber,
    subscriptions,
    message_attributes,
):
    if subscription_arn not in [None, subscriber["SubscriptionArn"]]:
        return
    filter_policy = json.loads(subscriber.get("FilterPolicy") or "{}")
    if not message_attributes:
        message_attributes = get_message_attributes(req_data)
    if not skip_checks and not check_filter_policy(filter_policy, message_attributes):
        LOG.info(
            "SNS filter policy %s does not match attributes %s", filter_policy, message_attributes
        )
        return
    if subscriber["Protocol"] == "sms":
        event = {
            "topic_arn": topic_arn,
            "endpoint": subscriber["Endpoint"],
            "message_content": req_data["Message"][0],
        }
        sns_backend.sms_messages.append(event)
        LOG.info(
            "Delivering SMS message to %s: %s",
            subscriber["Endpoint"],
            req_data["Message"][0],