fix: configure i18next to not return empty strings

i18next-parser.config.ts

@@ -10,9 +10,7 @@ export default {
 	contextSeparator: '_',
 	createOldCatalogs: false,
 	defaultNamespace: 'translation',
-	defaultValue: function (locale, namespace, key, value) {
-		return key;
-	},
+	defaultValue: '',
 	indentation: 2,
 	keepRemoved: false,
 	keySeparator: false,

src/lib/i18n/index.ts

@@ -56,6 +56,7 @@ i18next
 			default: ['en']
 		},
 		ns: 'translation',
+		returnEmptyString: false,
 		interpolation: {
 			escapeValue: false // not needed for svelte as it escapes by default
 		}