Way to report measurement by name

Hello!

(There is a gist covering this with examples if it is simpler: https://gist.github.com/fpapado/9163e02e6cf303d5b7bfe113ca5e964f)

I am trying to use nanotiming and abstract over the start/measure/report logic. One issue I am running into is the ordering of timers in the example:

```js
var timings = performance.getEntries()
var timing = timings[timings.length - 1]
console.log(timing.name, timing.duration) // log the last entry
performance.clearMeasures(timing.name) // be a good citizen and free after use
```

This assumes that the relevant measurement is always the last one in the result of `getEntries()`. However, if timers are overlapping, then this is no longer the case.

A way to pick a measurement by its name would then be desirable.
Looking at the documentation for perf_hooks, I see that [`getEntriesByName` is a method that's available](https://nodejs.org/api/perf_hooks.html#perf_hooks_performance_getentriesbyname_name_type).

The measurement name (name + '[' + uuid + ']') is available inside nanotiming, but does not get reported directly, for example in the callback. Changing / adding to line 34 would make this possible
```js
if (cb) cb(err, measureName) // or cb(err, name, measureName)
```

Is this something that makes sense to add? Have you had any similar issues with this or am I just missing something? Thanks in advance :)

Start at line 34 where the callback is invoked, then review the example using performance.getEntries() and the perf_hooks getEntriesByName documentation. Check the gist for the intended timing flow and decide how the measurement name should be exposed through the callback; done means callers can identify the measurement without relying on entry ordering.

Written by the indexing model from the issue text.