[BUG] (type-safe-api) array responses produce broken code

### Describe the bug

Returning an array as the top level response from an operation causes code to be generated which does not compile.

### Expected Behavior

Working code.

### Current Behavior

Broken code eg:

```ts
const marshal = (statusCode: number, responseBody: any): string => {
let marshalledBody = responseBody;
switch(statusCode) {
case 200:
marshalledBody = JSON.stringify(ArrayToJSON(marshalledBody));
break;
```

### Reproduction Steps

Use spec from https://github.com/aws/aws-pdk/issues/863

### Possible Solution

_No response_

### Additional Information/Context

_No response_

### PDK version used

0.23.70

### What languages are you seeing this issue on?

Typescript, Java, Python

### Environment details (OS name and version, etc.)

osx

Start with the reproduction spec referenced in issue #863 and generate the TypeScript, Java, and Python outputs for an operation whose top-level response is an array. Compare the generated response marshalling with the failing TypeScript example; done means all generated outputs compile and correctly serialize array responses.

Written by the indexing model from the issue text.