[BUG] Translations: different strings for plurals

Created by: MasterGroosha

• I checked the release notes for known issues
• I checked the existing issues
• I checked that the issue is not related to my instance configuration, and that my instance has the latest version of pixelfed

Currently, there's only one string for likes, reposts and so on. "11 likes", "12 likes" etc. However, many languages have different forms, like "one", "two", "many" and "other".