### 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_
from localstack.utils.aws.aws_responses import (
    create_sqs_system_attributes,
    parse_urlencoded_data,
    requests_response_xml,
    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"]
SKIP_PERSISTENCE_ACTIONS = [
    "Subscribe",
    "ConfirmSubscription",
    "Unsubscribe",
]
SNS_PROTOCOLS = [
    "http",