feat(vocab): add lesson and completed lesson vocab pool endpoints

- Implemented new endpoints in VocabController for retrieving vocab pools based on lessons and completed lessons.
- Updated vocabRouter to include routes for accessing lesson vocab pools and completed lesson vocab pools.
- Enhanced VocabService with methods to extract vocab from exercises and lesson didactics, improving vocabulary retrieval for users.
- Modified VocabPracticeDialog and VocabCourseView components to support new vocab pool functionalities, enhancing user experience in vocabulary practice.

frontend/src/views/social/VocabCourseView.vue

@@ -88,6 +88,13 @@
               >
                 {{ getLessonProgress(lesson.id)?.completed ? $t('socialnetwork.vocab.courses.review') : $t('socialnetwork.vocab.courses.start') }}
               </button>
+              <button
+                v-if="getLessonProgress(lesson.id)?.completed"
+                @click="openLessonPractice(lesson)"
+                class="btn-edit"
+              >
+                Im Trainer üben
+              </button>
               <button v-if="isOwner" @click="editLesson(lesson.id)" class="btn-edit">{{ $t('socialnetwork.vocab.courses.edit') }}</button>
               <button v-if="isOwner" @click="deleteLesson(lesson.id)" class="btn-delete">{{ $t('general.delete') }}</button>
             </div>
@@ -99,6 +106,8 @@
       </div>
     </div>
 
+    <VocabPracticeDialog ref="practiceDialog" />
+
     <!-- Add Lesson Dialog -->
     <div v-if="showAddLessonDialog" class="dialog-overlay" @click="showAddLessonDialog = false">
       <div class="dialog" @click.stop>
@@ -138,9 +147,11 @@
 import { mapGetters } from 'vuex';
 import apiClient from '@/utils/axios.js';
 import { confirmAction, showApiError, showInfo, showSuccess } from '@/utils/feedback.js';
+import VocabPracticeDialog from '@/dialogues/socialnetwork/VocabPracticeDialog.vue';
 
 export default {
   name: 'VocabCourseView',
+  components: { VocabPracticeDialog },
   props: {
     courseId: {
       type: String,
@@ -325,6 +336,12 @@ export default {
     openLesson(lessonId) {
       this.$router.push(`/socialnetwork/vocab/courses/${this.courseId}/lessons/${lessonId}`);
     },
+    openLessonPractice(lesson) {
+      this.$refs.practiceDialog?.open?.({
+        courseId: this.courseId,
+        lessonId: lesson.id
+      });
+    },
     openLessonAssistant(lessonId) {
       this.$router.push(`/socialnetwork/vocab/courses/${this.courseId}/lessons/${lessonId}?assistant=1`);
     },