Include trace ID in query-frontend response logs

The query frontend logs helpful messages for every API response like this:

	level.Info(logger).Log(
		"msg", "query range response",
		"tenant", tenantID,
		"query", req.Query,
		"range_nanos", req.End-req.Start,
		"max_series", req.MaxSeries,
		"duration_seconds", durationSeconds,
		"request_throughput", float64(resp.Metrics.InspectedBytes)/durationSeconds,
		"total_requests", resp.Metrics.TotalJobs,
		"total_blockBytes", resp.Metrics.TotalBlockBytes,
		"total_blocks", resp.Metrics.TotalBlocks,
		"completed_requests", resp.Metrics.CompletedJobs,
		"inspected_bytes", resp.Metrics.InspectedBytes,
		"inspected_traces", resp.Metrics.InspectedTraces,
		"inspected_spans", resp.Metrics.InspectedSpans,
		"partial_status", resp.Status,
		"partial_message", resp.Message,
		"num_response_series", len(resp.Series),
		"error", err)

We need to include trace ID, so we can easily navigate from the log to the trace for that request. This is probably a straight-forward fix because we already have traces along the read path, but I'd like to double check - was this a simple miss, or is there a reason it wasn't included in the first place?