perf_hooks: include uv info to perf json output

Author: jasnell

lib/internal/perf/nodetiming.js

@@ -164,6 +164,7 @@ class PerformanceNodeTiming {
       loopStart: this.loopStart,
       loopExit: this.loopExit,
       idleTime: this.idleTime,
+      uvMetricsInfo: this.uvMetricsInfo,
     };
   }
 }