Properly initialize content handler logging

[AndreRicardo-Zoetis]

I know you just cleared all Pull Requests, congrats! 😅

Fix #780 show curl logs.

While testing noticed that logLevel was not passed to contentDownloader, needed to pass logLevel so it works as expected for different -l parameters.

do-client logs were also missing, added initialization now.

deliveryoptimization is harder to test for us but did a full build and could see the do_download logs now:

Other changes:

• Added clean up logic when the library is being unloaded and renamed variable for consistency.

[Nox-MSFT]

@AndreRicardo-Zoetis - thanks for the PR. The changes look good, but I’m a bit concerned this could break others who have built custom content download handlers. We may want to consider a backward‑compatible approach (e.g., build flag or runtime check) to support both old and new ABIs.

[AndreRicardo-Zoetis]

@AndreRicardo-Zoetis - thanks for the PR. The changes look good, but I’m a bit concerned this could break others who have built custom content download handlers. We may want to consider a backward‑compatible approach (e.g., build flag or runtime check) to support both old and new ABIs.

Ok, but won't they have the same problem of the severity not being passed? Are these customers seeing their logs without the parameter?

Also the initializeData is only needed from what I can tell in do-client, while the log level is used by both.