feat(vocab): implement user vocab lesson progress reset functionality

- Added `resetUserVocabLessonProgress` method in `AdminController` to allow admins to reset a user's progress for a specific vocab lesson.
- Introduced corresponding route in `adminRouter` for the new reset functionality.
- Enhanced `VocabService` with methods to purge lesson progress for users, ensuring that only the specified lesson's progress is affected.
- Updated UI components in `UsersView` to facilitate the selection of courses and lessons for resetting progress, including confirmation dialogs and loading states.
- Added localization support for the new reset functionality across multiple languages.
- Implemented reset functionality in `VocabLessonView` for users to reset their own lesson progress.

backend/routers/vocabRouter.js

@@ -48,6 +48,7 @@ router.delete('/courses/:courseId/enroll', vocabController.unenrollFromCourse);
 router.get('/courses/:courseId/progress', vocabController.getCourseProgress);
 router.get('/lessons/:lessonId', vocabController.getLesson);
 router.put('/lessons/:lessonId/progress', vocabController.updateLessonProgress);
+router.delete('/lessons/:lessonId/progress', vocabController.resetLessonProgress);
 
 // Grammar Exercises
 router.get('/grammar/exercise-types', vocabController.getExerciseTypes);