feat(vocab): implement SRS features and enhance vocabulary management

- Added new endpoints in vocabController for retrieving SRS due items and reviewing SRS items, improving spaced repetition support.
- Updated vocabService to handle SRS item creation and scheduling, ensuring effective tracking of vocabulary exposure.
- Enhanced vocabRouter with new routes for SRS functionalities, facilitating user interaction with spaced repetition features.
- Modified VocabPracticeDialog and VocabCourseView to integrate SRS due items, providing users with timely review opportunities.
- Updated translations and UI elements to reflect new SRS features, enhancing user experience and accessibility.

backend/routers/vocabRouter.js

@@ -35,9 +35,11 @@ router.post('/courses/find-by-code', vocabController.getCourseByShareCode);
 router.get('/courses/:courseId/completed-lesson-vocabs', vocabController.getCompletedLessonVocabPool);
 router.get('/courses/:courseId/dictionary', vocabController.getCourseDictionary);
 router.get('/courses/:courseId/distractor-pool', vocabController.getVocabDistractorPool);
+router.get('/courses/:courseId/srs/due', vocabController.getCourseSrsDue);
 router.get('/courses/:courseId', vocabController.getCourse);
 router.put('/courses/:courseId', vocabController.updateCourse);
 router.delete('/courses/:courseId', vocabController.deleteCourse);
+router.post('/srs/review', vocabController.reviewSrsItem);
 
 // Lessons
 router.post('/courses/:courseId/lessons', vocabController.addLessonToCourse);