### 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_
"""
    The SQS Batch publisher is responsible for publishing batched SNS messages to a subscribed SQS queue using
    `SQS.send_message_batch`. This allows to make use of SQS batching capabilities.
    See https://docs.aws.amazon.com/sns/latest/dg/sns-batch-api-actions.html
    https://docs.aws.amazon.com/sns/latest/api/API_PublishBatch.html
    https://docs.aws.amazon.com/AWSSimpleQueueService/latest/APIReference/API_SendMessageBatch.html
    """
    def _publish(self, context: SnsBatchPublishContext, subscriber: SnsSubscription):
        entries = []
        sqs_system_attrs = create_sqs_system_attributes(context.request_headers)
        
        failure_map = {}
        for index, message_ctx in enumerate(context.messages):
            message_body = self.prepare_message(message_ctx, subscriber)
            sqs_kwargs = self.get_sqs_kwargs(message_ctx, subscriber)
            entry = {"Id": f"sns-batch-{index}", "MessageBody": message_body, **sqs_kwargs}
            
            failure_map[entry["Id"]] = {
                "context": message_ctx,
                "entry": entry,
            }
            if sqs_system_attrs:
                entry["MessageSystemAttributes"] = sqs_system_attrs
            entries.append(entry)
        try:
            queue_url = sqs_queue_url_for_arn(subscriber["Endpoint"])
            region = extract_region_from_arn(subscriber["Endpoint"])
            sqs_client = connect_to(region_name=region).sqs.request_metadata(
                source_arn=subscriber["TopicArn"], service_principal="sns"
            )