i18n - support defining plural counts dynamically

Feature Request

Let's say you got this:

popup:
  speed:
    affectedVideos:
      0: Żaden film nie miał zmienionej prędkości.
      1: 1 film miał zmienioną prędkość.
      n: $1 filmów miało zmienioną prędkość.

The 3rd n option is not gramatically valid for all cases in Polish. It'd need to be split into two cases:

• 2-4 - "$1 filmy miały zmienioną prędkość."
• 5-inf - "$1 filmów miało zmienioną prędkość."

I tried adding all 2, 3 and 4 separately as repeats, but WXT throws an error that the plural count is unknown, I suggest adding minimum the option to define translations for any counts. It'd be great if it also supported ranged like mentioned 2-4 - I don't know if that's what i18n libs do usually, I'm not expert at them, but I know bunch of them definitely support more cases than just 0/1/n.

Is your feature request related to a bug?

N/A

What are the alternatives?

You tell me. Well, one alternative is for sure to change the string to be different, e.g. "Liczba filmów ze zmienioną prędkością: $1." in this case, as I just did, but it's not always a possibility.

Additional context

N/A

The issue names no files, entry points, or tests. Start by locating WXT's i18n plural-count parsing and its existing pluralization tests, then determine how arbitrary counts and ranges such as 2-4 should be represented. Done means Polish-style plural cases can be defined without an unknown-count error and are covered by tests.