### 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_
SnsApplicationPlatforms,
    SnsMessage,
    SnsStore,
    SnsSubscription,
)
from localstack.utils.aws.arns import (
    extract_region_from_arn,
    extract_resource_from_arn,
    parse_arn,
    sqs_queue_url_for_arn,
)
from localstack.utils.aws.aws_responses import create_sqs_system_attributes
from localstack.utils.aws.client_types import ServicePrincipal
from localstack.utils.aws.dead_letter_queue import sns_error_to_dead_letter_queue
from localstack.utils.cloudwatch.cloudwatch_util import store_cloudwatch_logs
from localstack.utils.objects import not_none_or
from localstack.utils.strings import long_uid, md5, to_bytes
from localstack.utils.time import timestamp_millis
LOG = logging.getLogger(__name__)
@dataclass
class SnsPublishContext:
    message: SnsMessage
    store: SnsStore
    request_headers: Dict[str, str]
@dataclass
class SnsBatchPublishContext:
    messages: List[SnsMessage]
    store: SnsStore
    request_headers: Dict[str, str]
class TopicPublisher(abc.ABC):