Update performance test scripts to enhance clarity and consistency

- Set `TEST_MODE` before loading relevant monitoring scripts in `test_analytics_query_performance.sh` and `test_wms_monitoring_overhead.sh` to ensure a consistent test environment.
- Cleaned up whitespace and improved formatting in multiple test scripts, enhancing readability and maintainability.
- Updated `test_ddosProtection_load.sh` to replace `check_attack_detection` with `detect_ddos_attack` for better clarity in DDoS detection logic.
- Ensured that alert deduplication is disabled in `test_stress_metrics.sh` for accurate testing outcomes, allowing all alerts to be recorded.
- Added comments to clarify the purpose of certain operations, improving documentation within the test scripts.

Author: angoca