[event-hubs] Move express sample to root /samples

[witemple-msft]

In #14074, I suggested relocating a potential storage sample that uses Azure Functions to /samples, reasoning being that only samples that explicitly deal with the package API should be included in the package's own samples directory.

We should consider doing the same for the expressSample in Event Hubs, since it's in basically the same situation of being an integration sample that lives within a specific package's repo.

If this becomes a pattern, then we probably will want to take some time to think about how to organize the root /samples folder to prevent it exploding.

CC @ramya-rao-a

[github-actions]

Hi @witemple-msft, we deeply appreciate your input into this project. Regrettably, this issue has remained inactive for over 2 years, leading us to the decision to close it. We've implemented this policy to maintain the relevance of our issue queue and facilitate easier navigation for new contributors. If you still believe this topic requires attention, please feel free to create a new issue, referencing this one. Thank you for your understanding and ongoing support.