IGNITE-28885 Add JMX Prometheus Exporter to Ducktests for Monitoring

[EgorBaranovEnjoysTyping]

Motivation

    Prometheus does not support the JMX protocol natively; it only scrapes metrics exposed over HTTP in its own text format. A bridge (JVM agent) is required to make JVM-level metrics accessible to Prometheus.

    This task integrates jmx_prometheus_javaagent into the ducktests framework so that every server/client node exposes JVM memory and GC metrics at :8083/metrics in Prometheus format. This enables Grafana
    dashboards that mirror the jconsole "Memory" tab (heap, non-heap, memory pools, GC collection count/time).

Changes

    1. Dockerfile (modules/ducktests/tests/docker/Dockerfile)
     - Download and install jmx_prometheus_javaagent-1.1.0.jar to /opt/jmx_exporter.jar

    2. jmx_exporter package (modules/ducktests/tests/ignitetest/services/utils/jmx_exporter/)
     - {}init{}.py — helper module with:
       - JmxExporterParams — settings from globals config (enabled, port)
       - get_jmx_exporter_params() — parse globals
       - is_jmx_exporter_enabled() — check if enabled
       - get_jmx_exporter_yml_content() — read bundled YAML content
       - jmx_agent_jvm_opt() — build -javaagent JVM option string
     - jmx_exporter.yml — rule mappings for JVM memory and GC metrics:
       - jvm_memory_heap_bytes_{used,max,committed,init}
       - jvm_memory_nonheap_bytes_{used,max,committed,init}
       - jvm_memory_pool_usage_bytes{pool,attribute}
       - jvm_memory_pool_collection_bytes{pool,attribute}
       - jvm_gc_collection_count_total{gc}
       - jvm_gc_collection_time_seconds_total{gc}

    3. ignite_spec.py (modules/ducktests/tests/ignitetest/services/utils/ignite_spec.py)
     - In __get_default_jvm_opts(): append -javaagent:/opt/jmx_exporter.jar={port}:{config_dir}/jmx_exporter.yml when jmx_exporter.enabled is true in globals

    4. ignite_aware.py (modules/ducktests/tests/ignitetest/services/utils/ignite_aware.py)
     - In init_persistent(): download jmx_exporter.jar to node if not present (idempotent: test -f || curl)
     - In _prepare_configs(): create jmx_exporter.yml in the node's config directory from bundled resource