[21188] Example Refactor: Request-Reply

Description

This PR refactors the request-reply example.

[x] Commit messages follow the project guidelines.
[x] The code follows the style guidelines of this project.
[x] Tests that thoroughly check the new feature have been added/Regression tests checking the bug and its fix have been added; the added tests pass locally
N/A: Any new/modified methods have been properly documented using Doxygen.
N/A: Any new configuration API has an equivalent XML API (with the corresponding XSD extension)
N/A: Changes are backport compatible: they do NOT break ABI nor change library core behavior.
N/A: Changes are API compatible.
[x] New feature has been added to the versions.md file (if applicable).
N/A: New feature has been documented/Current behavior is correctly described in the documentation.
N/A: Applicable backports have been included in the description.

[x] The PR has a milestone assigned.
[x] The title and description correctly express the PR's purpose.
[x] Check contributor checklist is correct.
N/A: If this is a critical bug fix, backports to the critical-only supported branches have been requested.
[ ] Check CI results: changes do not issue any warning.
[ ] Check CI results: failing tests are unrelated with the changes.