feat: add listTrainingStyles to API utility functions

- Introduced listTrainingStyles function to the API utility, enhancing the capabilities for managing training styles.
- This addition supports improved data retrieval for training-related features in the application.

frontend/src/utils/api.js

@@ -822,6 +822,7 @@ export const api = {
   deleteFocusArea,
   getAdminHierarchy,
   listStyleDirections,
+  listTrainingStyles,
   createStyleDirection,
   updateStyleDirection,
   deleteStyleDirection,