Add root-level cluster_name and standardize collection_interval for OpenTelemetry features

[Paamicky]

Description of the issue

The OpenTelemetry config section had two inconsistencies: cluster_name was required per-component, forcing customers to repeat the same cluster value for every feature, and the collection interval field name differed across features (metrics_collection_interval vs collection_interval). This has been updated to use the newer version collection_interval

Description of changes

• Root-level cluster_name: Moved to opentelemetry.cluster_name. A single value now applies to all features (Container Insights, Prometheus, Host Metrics, OTLP). Container Insights and Prometheus require it; Host Metrics and OTLP apply it when present.
• Standardized collection_interval: All OpenTelemetry features now use collection_interval with a 30-second default. Host Metrics renamed from metrics_collection_interval. Database Insights retains its own hardcoded intervals.
• Centralized validation: ClusterNameRegex moved to the common package. GetOtelClusterName and GetCollectionInterval added as shared helpers.
• Schema updated: schema.json reflects the new root-level cluster_name field and standardized collection_interval across features.

Tests

• Unit tests for GetOtelClusterName verifies root-level reads, env var is not used as fallback, empty config returns empty
• Unit tests for GetCollectionInterval verifies feature-level override, 30s default, zero/negative values ignored
• Updated golden file tests and confirm set_cluster_name processor appears in all applicable pipelines
• All existing translator tests pass

License

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