### 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_
topic_arn = sns_create_topic()["TopicArn"]
        fake_topic_arn = topic_arn + "fake-topic"
        with pytest.raises(ClientError) as e:
            aws_client.sns.publish_batch(
                TopicArn=fake_topic_arn,
                BatchRequestEntries=[
                    {
                        "Id": "1",
                        "Message": "Test Message with two attributes",
                        "Subject": "Subject",
                    }
                ],
            )
        snapshot.match("publish-batch-no-topic", e.value.response)
    @pytest.mark.aws_validated
    @pytest.mark.skip_snapshot_verify(
        paths=[
            "$.topic-attrs.Attributes.DeliveryPolicy",
            "$.topic-attrs.Attributes.EffectiveDeliveryPolicy",
            "$.topic-attrs.Attributes.Policy.Statement..Action",  # S
            "$.sub-attrs-raw-true.Attributes.SubscriptionPrincipal",
            "$.republish-batch-response-fifo.Successful..MessageId",  # T
            "$.republish-batch-response-fifo.Successful..SequenceNumber",  # T
        ]
    )
    @pytest.mark.parametrize("content_based_deduplication", [True, False])
    def test_publish_batch_messages_from_fifo_topic_to_fifo_queue(