Kubernetes Monitoring Helm chart v4: Biggest update ever!

Grafana's Kubernetes Monitoring Helm chart v4 is a major overhaul addressing real pain points from v3. Key changes include: converting destinations and collectors from lists to maps (enabling proper multi-file merging and named overrides), replacing hard-coded collector names with user-defined collectors using composable presets, making telemetry service deployments explicit to avoid surprise duplicates, splitting the overloaded clusterMetrics feature into three focused features, separating pod log collection methods into distinct features with native OTLP support, replacing the bulk labelsToKeep approach with explicit opt-in label declarations (reducing memory usage), and allowing granular control over individual profiler types. A migration tool is available to convert v3 values files to v4 format automatically.