feat: add runtime i18n API with manifest translations

test/runtime/events/runtime_event_dispatcher_test.dart

@@ -138,6 +138,7 @@ void main() {
       expect(script.events.map((event) => event.target), ['bad', 'good']);
     });
   });
+
 }
 
 RuntimeSession _activeSession() {
@@ -177,4 +178,10 @@ class _FakeScriptEngine implements ScriptEngine {
     }
     return GameDiff.empty;
   }
+
+  @override
+  void setTranslations({
+    required String locale,
+    required Map<String, Map<String, String>> translations,
+  }) {}
 }