feat(vocabLesson): add detailed review section for failed chapter exams

- Introduced a new review section that displays questions, user answers, and correct answers for failed chapter exams.
- Added localization entries for the review section in multiple languages, enhancing user experience and understanding of mistakes.
- Implemented logic to format and present failed exam details, improving feedback for learners.

frontend/src/i18n/locales/de/socialnetwork.json

@@ -544,6 +544,10 @@
                 "exerciseExamFailedTitle": "Mindestziel nicht erreicht",
                 "exerciseExamFailedBody": "Du hast {score}% der Fragen richtig beantwortet (Mindestziel: {target}%). Bitte übe weiter im Lernbereich. Nach {count} weiteren Trainerfragen ist die Kapitel-Prüfung wieder freigeschaltet – dann beginnst du mit allen Fragen von vorn.",
                 "exerciseExamFailedOk": "Verstanden",
+                "exerciseExamFailedReviewTitle": "Das war noch falsch",
+                "exerciseExamFailedQuestionLabel": "Frage",
+                "exerciseExamFailedYourAnswerLabel": "Deine Antwort",
+                "exerciseExamFailedNoAnswer": "Keine Antwort",
                 "exerciseStatusOpen": "Offen",
                 "exerciseStatusCorrect": "Erledigt",
                 "exerciseStatusRetry": "Nochmal prüfen",