[EUI] Fix EuiFilterButton badge i18n

[cee-chen]

Summary

closes elastic/eui#4786

I picked up a super simple EUI issue to familiarize myself more with EUI's i18n process and relationship with Kibana's i18n :)

I think this should solve the problem described in the linked issue above, but let me know if not!

Checklist

• Any text added follows EUI's writing guidelines, uses sentence case text and includes i18n support

[kibanamachine]

💚 Build Succeeded

• continuous-integration/kibana-ci/pull-request
• Commit: 3d825e0
• Storybooks Preview

Metrics [docs]

Page load bundle

Size of the bundles that are downloaded on every page load. Target size is below 100kb

id	before	after	diff
core	423.6KB	423.8KB	+215.0B

To update your PR or re-run it, just comment with:
@elasticmachine merge upstream

[afharo]

The fix in Kibana LGTM. However, I wonder if we should fix it in the EUI library so any other consumers can take advantage of it?

[thompsongl]

I wonder if we should fix it in the EUI library

Yeah @constancecchen we'll want first change it in EUI and then update the i18n_eui_mapping file here after it's released during the upgrade.

[cee-chen]

Ahh great calls! I actually did spike out a more opinionated change in EUI, basically splitting up into 2 different strings rather than trying to make a single string conditional. I think it will get translated better that way and possibly more smoothly in different languages, rather than trying to chop it up based on English. What do y'all think? I'll open up the PR for EUI, would love thoughts there :)

[thompsongl]

That diff looks good to me, @constancecchen!
The path remains the same: make the change in EUI and handle updating i18n_eui_mapping during the upgrade PR

[cee-chen]

Closing in favor of elastic/eui#5061