### 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_
kwargs = self.get_sqs_kwargs(message_ctx, subscriber)
                sns_error_to_dead_letter_queue(
                    subscriber,
                    msg_body,
                    str(exc),
                    **kwargs,
                )
            if "NonExistentQueue" in str(exc):
                LOG.debug("The SQS queue endpoint does not exist anymore")
                
                
                
class HttpTopicPublisher(TopicPublisher):
    """
    The HTTP(S) publisher is responsible for publishing the SNS message to an external HTTP(S) endpoint which subscribed
    to the topic. It will create an HTTP POST request to be sent to the endpoint.
    See https://docs.aws.amazon.com/sns/latest/dg/sns-http-https-endpoint-as-subscriber.html
    """
    def _publish(self, context: SnsPublishContext, subscriber: SnsSubscription):
        message_context = context.message
        message_body = self.prepare_message(message_context, subscriber)
        try:
            message_headers = {
                "Content-Type": "text/plain",
                
                
                "x-amz-sns-message-type": message_context.type,
                "x-amz-sns-message-id": message_context.message_id,
                "x-amz-sns-topic-arn": subscriber["TopicArn"],
                "User-Agent": "Amazon Simple Notification Service Agent",