Show more precise time duration in reporter epilogue

[yomed]

Describe the solution you'd like
At the end of a test run, the total duration currently shows a rounded value, like 1m. It would be great if this was more precise, like 1m 12s 354ms or 00:01:12.354.

Additional context
The relevant code appears to be in the base reporter epilogue, here:

mocha/lib/reporters/base.js

Line 349 in 1412dc8

Base.consoleLog(fmt, stats.passes || 0, milliseconds(stats.duration));

[yomed]

This should be straightforward once ms supports decimal places vercel/ms#125

[JoshuaKGoldberg]

Per #4797 (comment):

No, we are not planing to change the time format in our reports. Quite a few third-party reporters are using mocha/lib/reporters/base.js, so this would be a breaking change.

You can create your own reporter and implement your desired time format.