Respect nested/structured log format instead of flattening attributes

[jackgopack4]

Currently, OTLP logs are transformed via pkg/otlp/logs.Translator.MapLogs(...)

This maps any key/value pairs in the log to AdditionalProperties in the datadog V2 API which, as of v2.31 requires map[string][string].

Currently, arrays in nested logs are "flattened" via a flattenAttributes function introduced by the fix for open-telemetry/opentelemetry-collector-contrib#26382. This maps Attributes from OTLP logs to map<string, string>. However, this does not align with the OpenTelemetry Logs Data Model which specifies attributes should be type map<string,any>. Nested maps are currently handled appropriately; this change is only necessary to properly support arrays in nested logs

Relates to DataDog/datadog-agent#28598