vtl2_settings_worker: additional tracing

[mattkur]

While debugging some failures to modify VTL2 settings, I noticed that we didn't have explicit logging in some error paths. Add that logging.

[Copilot]

Pull Request Overview

This PR adds explicit tracing/logging statements to improve debugging capabilities in the VTL2 settings worker. The changes provide better visibility into error paths that previously lacked explicit logging.

• Added trace logging for received VTL2 settings
• Added warning logs for errors during VTL2 configuration preparation and application phases
• Refactored settings parsing logic to enable intermediate logging

[smalis-msft]

I think the idea is that this error probably gets logged upstream, but this is goodness too, especially if they aren't actually logged upstream.

[mattkur]

I think the idea is that this error probably gets logged upstream, but this is goodness too, especially if they aren't actually logged upstream.

I think so too. But I'm going to hold off merging this one until I fully understand what's going on. I had errors, yet I saw no error logs.

[github-actions]

At least one Petri test failed.