fix(i18n): every counted string is a plural pair, so one reads singular

"1 seasons", "Synced 1 subscriptions", "1 video(s) were skipped": 21 English
strings carried {{count}} in one plain key and read plural at one. Each is a
_one/_other pair now (Hungarian keeps one form for both), and so is every other
counted string, so the next wording change is a plural too. A contract test
holds the rule for every locale file.

frontend/src/i18n/locales/hu/editor.json

@@ -18,7 +18,8 @@
   "willReencode": "Újrakódolás lesz",
   "willCopy": "Azonnali (másolás)",
   "create": "Klip létrehozása",
-  "createN": "{{count}} klip létrehozása",
+  "createN_one": "{{count}} klip létrehozása",
+  "createN_other": "{{count}} klip létrehozása",
   "created_one": "{{count}} klip a letöltésekhez adva",
   "created_other": "{{count}} klip a letöltésekhez adva",
   "failed": "Nem sikerült létrehozni a klipet",