[Bug]: Cloudfront Signer is not replaced

### Self-service

- [ ] I'd be willing to implement a fix

### Describe the bug

Running transform containing a Cloudfront Signer does not transform, but only remove the legacy import

### Steps to reproduce

```ts
import { CloudFront } from "aws-sdk";
//....
export async function cloudfrontSignUrl(url, expires_at_ms, options = {}) {
// ...
let signer = new CloudFront.Signer(accessKeyID, privateKeyContents);
return signer.getSignedUrl({ url, expires: expires_at_ms, ...options });
}
```

### Observed behavior

* Removes `import { CloudFront } from "aws-sdk";`

### Expected behavior

Should result in

```ts
import { getSignedUrl } from "@aws-sdk/cloudfront-signer";
// ...
export async function cloudfrontSignUrl(url, expires_at_ms, options = {}) {
// ...
return getSignedUrl({ url, privateKey: privateKeyContents, keyPairId: accessKeyID, dateLessThan: expires_at_ms})
}
```

### Environment

```shell
aws-sdk-js-codemod: 0.28.2
- jscodeshift: 0.15.0
- recast: 0.23.4
```

### Additional context

_No response_

Start by locating the codemod transform that handles CloudFront.Signer and the existing tests or fixtures for AWS SDK migrations. Reproduce the example, then add coverage showing that the legacy import and signer call become the @aws-sdk/cloudfront-signer import and getSignedUrl usage described in the issue.

Written by the indexing model from the issue text.