refactor(bisaya-course): enhance pedagogy logic for German lessons

- Updated the `getGermanForBisayaLessonPedagogy` function to include lesson titles for improved didactic mode determination, specifically adding support for 'contrast_training'.
- Modified multiple scripts to utilize the updated pedagogy function, ensuring consistent application of the new logic across various course phases.
- Enhanced the VocabService to recognize and handle 'contrast_training' as a didactic mode, improving lesson management and user experience.
- Updated UI components to reflect the new didactic mode, ensuring clarity in lesson presentation.

frontend/src/views/social/VocabLessonView.vue

@@ -1972,6 +1972,8 @@ export default {
           return 'Neuer Stoff';
         case 'guided_dialogue':
           return 'Geführter Dialog';
+        case 'contrast_training':
+          return 'Kontrasttraining';
         case 'pattern_drill':
           return 'Mustertraining';
         case 'real_life_scenario':