Set default digital number format to minFrac=0, maxFrac=9

[sffc]

It's a bit late to be making changes like this, but since we keep approving them, I'll suggest another

new Intl.DurationFormat("en", { style: "digital" }).format({ seconds: 1, milliseconds: 230 });

Current output: "0:00:01"

I think the above line should display "0:00:01.23".

This can be accomplished by setting the default second format to minFrac=0, maxFrac=9.

[ryzokuken]

I support the change of defaults but we should nonetheless discuss, especially the change of options for DurationFormat.

[sffc]

Yes. There are a few options here:

1. Keep things as spec'd.
2. Change the default maximumFractionDigits to 9, but the fractionalDigits setter continues to work the same.
3. Change the default maximumFractionDigits to 9, and also change the options to be [min/max]imumFractionDigits instead of fractionalDigits.
4. Set the default fractionalDigits to undefined with the above proposed default behavior.
5. Add "auto" as a string value to fractionalDigits and set that as the default value.

[sffc]

TG2 approval: https://github.com/tc39/ecma402/blob/master/meetings/notes-2023-04-06.md#set-default-digital-number-format-to-minfrac0-maxfrac9-144

The group would like to move forward with option 4. We need an updated PR for that.