### 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_
self, conditions, attribute, field_exists: bool
    ):
        if not isinstance(conditions, list):
            conditions = [conditions]
        tpe = attribute.get("DataType") or attribute.get("Type") if attribute else None
        val = attribute.get("StringValue") or attribute.get("Value") if attribute else None
        if attribute is not None and tpe == "String.Array":
            try:
                values = json.loads(val)
            except ValueError:
                return False
            for value in values:
                for condition in conditions:
                    if self._evaluate_condition(value, condition, field_exists):
                        return True
        else:
            for condition in conditions:
                value = val or None
                if self._evaluate_condition(value, condition, field_exists):
                    return True
        return False
    def _evaluate_filter_policy_conditions_on_field(self, conditions, value, field_exists: bool):