[kafka-metrics] Update dependencies, align with OTel/DD best practices

[dineshg13]

• Update OTel Collector from 0.93.0 to 0.115.0
• Update JMX Metrics Gatherer JAR from 1.27.0 to 1.42.0
• Update OTel Java agent from v2.2.0 to v2.11.0
• Update Kafka client dependencies from 2.3.0/3.5.1 to 3.7.1
• Update Log4j from 2.22.1 to 2.24.3
• Pin Confluent Kafka/ZooKeeper images to 7.7.1 (was :latest)
• Switch base images from openjdk:17-buster to eclipse-temurin:17-jdk
• Upgrade JMX gatherer base from java11-debian11 to java17-debian11
• Add memory_limiter processor to all collector pipelines
• Add collection_interval to JMX receivers
• Add resource limits to all docker-compose services
• Add health checks for Kafka broker service
• Use condition-based depends_on for reliable startup ordering
• Add Kafka topic retention and auto-creation settings
• Add DD_SITE env var with default to docker-compose files
• Rename deprecated 'logging' exporter to 'debug' in JMX receiver config
• Fix EXPOSE ports (remove deprecated 55680/55679, add 4318)
• Remove deprecated docker-compose version field
• Add producer retry/backoff and idempotent configuration
• Add consumer resilience settings (auto-offset-reset, session timeout)
• Fix consumer App.java missing braces in for loop
• Use parameterized logging instead of string concatenation
• Add .env.example with required environment variables
• Add Makefile with build/run/clean targets
• Add inline documentation comments throughout configs
• Standardize log4j2.xml appender ordering across producer/consumer

What does this PR do?

Motivation