CNDB-16214: Fix client warnings not being propagated across async execution stages

[driftx]

What is the issue

When queries execute on async stages, ExecutorLocals containing ClientWarn.State are not being propagated causing warnings to be lost.

What does this PR fix and why was it fixed

Propagate ExecutorLocals across two thread transitions: caller thread to NATIVE_TRANSPORT_REQUESTS, and NATIVE_TRANSPORT_REQUESTS to async stage.

[github-actions]

Checklist before you submit for review

• This PR adheres to the Definition of Done
• Make sure there is a PR in the CNDB project updating the Converged Cassandra version
• Use NoSpamLogger for log lines that may appear frequently in the logs
• Verify test results on Butler
• Test coverage for new/modified code is > 80%
• Proper code formatting
• Proper title for each commit staring with the project-issue number, like CNDB-1234
• Each commit has a meaningful description
• Each commit is not very long and contains related changes
• Renames, moves and reformatting are in distinct commits
• All new files should contain the DataStax copyright header instead of the Apache License one

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
80.0% Coverage on New Code
31.6% Duplication on New Code

See analysis details on SonarQube Cloud

[cassci-bot]

✔️ Build ds-cassandra-pr-gate/PR-2151 approved by Butler

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Approved by Butler
See build details here