Currently, JFR tool formats the times with millisecond precision:

```
jdk.ThreadSleep {
  startTime = 10:48:56.668 (2025-03-13)
  duration = 100 ms
  time = 100 ms
  eventThread = "main" (javaThreadId = 3)
  stackTrace = [
    NotifyWaitLatency.work() line: 20
    NotifyWaitLatency.main(String[]) line: 4
    jdk.internal.reflect.DirectMethodHandleAccessor.invoke(Object, Object[]) line: 104
    java.lang.reflect.Method.invoke(Object, Object[]) line: 565
    com.sun.tools.javac.launcher.SourceLauncher.execute(MemoryContext, String[]) line: 254
  ]
}
```

In modern world, a lot can happen within a millisecond. So it would be better to default to microsecond precision. Both timesources supported by JFR (RDTSC and os::elapsed_counter()) have enough enough precision to satisfy microsecond output, so microseconds are meaningful.

I think durations should also be more precise -- for example to compute the endTime precisely from (startTime+duration), but that is a more controversial/style question, so I would like to handle it separately.