Missing usage information in npm azure/openai client response

### This issue is for a: (mark with an `x`)
```
- [ ] bug report -> please search issues before submitting
- [X] feature request
- [ ] documentation issue or request
- [ ] regression (a behavior that used to work and stopped in a new release)
```

### Minimal steps to reproduce
> On a Javascript application, install the package `@azure/openai` with `npm install @azure/openai`
> This installs version v1.0.0-beta.5
> Within the script, include:
> ``` Javascript
> const { OpenAIClient, AzureKeyCredential } = require("@azure/openai");
>
> const client = new OpenAIClient(CHATGPT_EP, new AzureKeyCredential(CHATGPT_KEY));
> const deploymentId = "DEPLOYMENT";
> const data = await client.getChatCompletions(deploymentId, CHAT_LIST);
>
> console.log(data);
> ```

### Any log messages given by the failure
>

### Expected/desired behavior
> I expected the response to include have a field of "usage" (with all the tokens consumption details) as presented in example response in:
> https://learn.microsoft.com/en-us/azure/ai-services/openai/reference#example-response-2

### OS and Version?
> Windows Chrome

### Versions
> Package version is v1.0.0-beta.5 (azure/openai on npm)

### Mention any other details that might be useful
I tried asking in the Microsoft Learn forum but was asked to raise an issue on the github repo, I'm not even sure if this is the right place.
However, I hope to know if it is still possible to somehow get that usage details included within the response without manually adding another tokenization package locally.
Appreciate your assistance.