### 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_
raise InvalidParameterException(
                f"Invalid parameter: FilterPolicyScope: Invalid value [{attribute_value}]. Please use either MessageBody or MessageAttributes"
            )
    elif attribute_name == "RawMessageDelivery":
        
        return
    elif attribute_name == "RedrivePolicy":
        try:
            dlq_target_arn = json.loads(attribute_value).get("deadLetterTargetArn", "")
        except json.JSONDecodeError:
            raise InvalidParameterException(
                "Invalid parameter: RedrivePolicy: failed to parse JSON."
            )
        try:
            parsed_arn = parse_arn(dlq_target_arn)
        except InvalidArnException:
            raise InvalidParameterException(
                "Invalid parameter: RedrivePolicy: deadLetterTargetArn is an invalid arn"
            )
        if topic_arn.endswith(".fifo"):
            if not parsed_arn["resource"].endswith(".fifo") or "sqs" not in parsed_arn["service"]:
                raise InvalidParameterException(
                    "Invalid parameter: RedrivePolicy: must use a FIFO queue as DLQ for a FIFO topic"
                )
def validate_message_attributes(message_attributes: MessageAttributeMap) -> None:
    """
    Validate the message attributes, and raises an exception if those do not follow AWS validation
    See: https://docs.aws.amazon.com/sns/latest/dg/sns-message-attributes.html
    Regex from: https://stackoverflow.com/questions/40718851/regex-that-does-not-allow-consecutive-dots
    :param message_attributes: the message attributes map for the message