Improve the exception handling

[pmalarme]

When there is an issue in the ai shopping cart service, we receive an error message without the reason of the error. It can be that Azure OpenAI is not well configured or that the service is unavailable. The exception when calling Azure OpenAI should be caught and handle by the REST controller to give a meaningful message to the front-end

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)

Versions

1.0.1

Mention any other details that might be useful

---

Thanks! We'll be in touch soon.