Add post build step to verify all artifacts were properly published

This step is to verify that after publishing all artifacts are available and downloadable.

1. Check that the respective nuget package has been published and downloadable on Nuget for all (SDK, DI and Otel)
2. Check that the SDK Zip file has been uploaded to s3 and downloadable.

The actual validation of the packages should be done before this step so that we do not publish something that will not work. If we cannot build and run a simple app, then we shouldn't publish the packages.