Use topicFromScopedName in a few systems

[nkoenig]

🦟 Bug fix

Summary

This may not be technically a bug fix, but it slightly simplifies some code.

Marking this as DRAFT for now. Need to see if this causes CI to complain.

Checklist

• [ ] Signed all commits for DCO
• [ ] Added tests
• [ ] Updated documentation (as needed)
• [ ] Updated migration guide (as needed)
• [ ] Consider updating Python bindings (if the library has them)
• [ ] codecheck passed (See contributing)
• [ ] All tests passed (See test coverage)
• [ ] While waiting for a review on your PR, please help review another open pull request to support the maintainers

Note to maintainers: Remember to use Squash-Merge and edit the commit message to match the pull request summary while retaining Signed-off-by messages.

[mjcarroll]

There is a segfault on Windows CI, I believe it is unrelated?

[nkoenig]

There is a segfault on Windows CI, I believe it is unrelated?

Yeah, looks unrelated.