Fixed container.name null bug when using Docker. Updated metadata enrichment for k8s environments. Added service cache

[LorenzoTettamanti]

Changes

• Added CF_DEBUG_LEVEL as environment variable in logger.rs to let users customize the logging level without rebuilding the image
• Added service cache and increased the read_perf_buffer drain time to 5s to prevent the CPU overload
• Fixed cargo.toml
• updated metrics.yaml image
• Updated metadata enrichment to mutually exclude docker and Kubernetes environements
• Updated Dockerfiles and build-conntracker script
• Fixed cfg attribute in consumer.rs (std::sync::Arc import)

Tests

• All checks passed
• Works with docker and kubernetes