### Is there an existing issue for this?

- [X] I have searched the existing issues

### Feature description

SNS allows for the publishing of messages to an SMS destination with a phone number. Those messages are logged and stored in the `SnsStore`, but there is no way to retrieve them for verification. The request here is to expose a new endpoint which returns SMS messages from the store, similar to the one made available to retrieve email messages sent via SES.

### 🧑‍💻 Implementation

The `SNSServicePlatformEndpointMessagesApiResource` class makes endpoints available for accessing platform endpoint messages sent via SNS. A similar resource class could be implemented to provide new endpoints for accessing SMS messages.

Given that interaction platform endpoint messages is exposed at the path `/_aws/sns/platform-endpoint-messages`, SMS message interaction would presumably be exposed at `/_aws/sns/sms-messages`. A `GET` endpoint could accept an optional `phoneNumber` query parameter to filter messages based on the destination phone number.

```python
class SNSServiceSMSMessagesApiResource:
  @route(sns_constants.SMS_MSGS_ENDPOINT, methods=["GET"])
    def on_get(self, request: Request):
      account_id = #...
      region = #...
      filter_phone_number = request.args.get("phoneNumber")
      # get store; conditionally filter messages based on filter_phone_number
```

### Anything else?

_No response_
}
            if message_context.type != "SubscriptionConfirmation":
                
                message_headers["x-amz-sns-subscription-arn"] = subscriber["SubscriptionArn"]
            
            
            
            elif message_context.type == "Notification" and is_raw_message_delivery(subscriber):
                message_headers["x-amz-sns-rawdelivery"] = "true"
            response = requests.post(
                subscriber["Endpoint"],
                headers=message_headers,
                data=message_body,
                verify=False,
            )
            delivery = {
                "statusCode": response.status_code,
                "providerResponse": response.content.decode("utf-8"),
            }
            store_delivery_log(message_context, subscriber, success=True, delivery=delivery)
            response.raise_for_status()
        except Exception as exc:
            LOG.info(
                "Received error on sending SNS message, putting to DLQ (if configured): %s", exc
            )
            store_delivery_log(message_context, subscriber, success=False)
            
            if message_context.type != "UnsubscribeConfirmation":
                sns_error_to_dead_letter_queue(subscriber, message_body, str(exc))
class EmailJsonTopicPublisher(TopicPublisher):