### 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_
message_context: SnsMessage, subscriber: SnsSubscription, success: bool, delivery: dict = None
):
    """Store the delivery logs in CloudWatch"""
    
    
    log_group_name = subscriber.get("TopicArn", "").replace("arn:aws:", "").replace(":", "/")
    log_stream_name = long_uid()
    invocation_time = int(time.time() * 1000)
    delivery = not_none_or(delivery, {})
    delivery["deliveryId"] = long_uid()
    delivery["destination"] = subscriber.get("Endpoint", "")
    delivery["dwellTimeMs"] = 200
    if not success:
        delivery["attemps"] = 1
    if (protocol := subscriber["Protocol"]) == "application":
        protocol = get_platform_type_from_endpoint_arn(subscriber["Endpoint"])
    message = message_context.message_content(protocol)
    delivery_log = {
        "notification": {
            "messageMD5Sum": md5(message),
            "messageId": message_context.message_id,
            "topicArn": subscriber.get("TopicArn"),
            "timestamp": datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S.%f%z"),
        },
        "delivery": delivery,
        "status": "SUCCESS" if success else "FAILURE",
    }
    log_output = json.dumps(delivery_log)
    return store_cloudwatch_logs(log_group_name, log_stream_name, log_output, invocation_time)
def create_subscribe_url(external_url, topic_arn, subscription_token):