### 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_
sns_backend = SNSBackend.get()
    sns_backend.sns_subscriptions.pop(topic_arn, None)
    sns_backend.sns_tags.pop(topic_arn, None)
def do_confirm_subscription(topic_arn, token):
    sns_backend = SNSBackend.get()
    for k, v in sns_backend.subscription_status.items():
        if v["Token"] == token and v["TopicArn"] == topic_arn:
            v["Status"] = "Subscribed"
def do_subscribe(topic_arn, endpoint, protocol, subscription_arn, attributes, filter_policy=None):