Track scheduler queue timing metadata

[yoshifuminakamura]

Summary

• preserve queue timing source metadata in Result JSON
• summarize explicit scheduler queue timing separately from reported queue timing
• mark locally collected queue timing as not measured until runner or scheduler metadata is available

Tests

• .venv/bin/pytest result_server/tests/test_performance_telemetry.py result_server/tests/test_portal_list_templates.py -q
• bash scripts/tests/test_result_common_json_contract.sh
• bash scripts/tests/test_process_and_send_results.sh
• bash scripts/tests/test_result_profile_data.sh
• shellcheck -S error -f gcc scripts/collect_timing.sh scripts/result.sh scripts/tests/test_process_and_send_results.sh scripts/tests/test_result_common_json_contract.sh scripts/tests/test_result_profile_data.sh