fix: add string return type to i18n._ (#1081)

Co-authored-by: Tanner Lyons <tanner.lyons@smartsheet.com>

Author: tannerlyons

packages/core/src/i18n.ts

@@ -193,7 +193,7 @@ export class I18n extends EventEmitter<Events> {
 
 
     // hack for parsing unicode values inside a string to get parsed in react native environments
-    if (isString(translation) && /\\u[a-fA-F0-9]{4}/g.test(translation)) return JSON.parse(`"${translation}"`)
+    if (isString(translation) && /\\u[a-fA-F0-9]{4}/g.test(translation)) return JSON.parse(`"${translation}"`) as string;
     if (isString(translation)) return translation
 
     return interpolate(