Improve number formatting

[micahmo]

Pull Request Description

This PR introduces a couple of changes related to number formatting.

I updated formatNumberToK to use the intl package's NumberFormat.compact() format rather than formatting it ourselves. There wasn't anything wrong with our code, but this is cleaner! It does make some small improvements like dropping trailing zeros (49.0K -> 49K).

I also updated search results a bit. We previously displayed the full subscriber count unformatted, which was a bit hard to read (like 45827). We could pare it down using ToK, but since we have plenty of room to display the full number, I used decimalPatternDigits instead. It would format the previous number as 45,827 (which I find much easier to read!). And since this is coming from intl, it will be locale-specific (e.g., . instead of ,).

Issue Being Fixed

Issue Number: N/A

Screenshots / Recordings

Checklist

• Did you update CHANGELOG.md?
• Did you use localized strings where applicable?
• Did you add semanticLabels where applicable for accessibility?

[hjiangsu]

LGTM!