Add support for ordinals in `NumberFormat`

[putnokiabel]

Is your feature request related to a problem? Please describe. I want to format a number with an ordinal suffix (e.g. "1st", "2nd", "3rd", "205th") in a localized way, as different languages have different ordinal suffixes.

Describe the solution you'd like I would like a NumberFormat that formats a number with an ordinal suffix, e.g.

factory NumberFormat.ordinal({String? locale});

, similar to NumberFormat.compact.

Describe alternatives you've considered I'm currently using a custom solution, however this obviously only works in English and is not localized.

extension Ordinals on int {
  String get ordinal {
    switch (this % 10) {
      case 1:
        return '${this}st';
      case 2:
        return '${this}nd';
      case 3:
        return '${this}rd';
      default:
        return '${this}th';
    }
  }
}

I've also considered using native libraries (as all platforms supported by Flutter have native support for this), but this would mean that:

1. I have to maintain a native library for this functionality
2. It would likely mean that formatting the numbers needs to happen asynchronously (since we need to wait on a PlatformChannel) which is obviously not ideal if you just want to display a string.

Additional context This issue is not a duplicate of https://github.com/dart-lang/i18n/issues/163, as this functionality does not inherently involve formatting dates, it's purely related to formatting numbers, and should therefore likely be an addition to NumberFormat.