feat(VocabPracticeDialog): implement SRS session management and enhance UI feedback

- Added support for spaced repetition system (SRS) session management, allowing users to resume practice sessions with due items.
- Introduced new UI elements to display SRS session status, including total due, completed, and remaining items.
- Enhanced localization for SRS-related messages in multiple languages, improving user experience and clarity.
- Updated methods for saving and loading SRS session data to local storage, ensuring persistence across sessions.

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

@@ -452,6 +452,9 @@
                 "wrong": "Falsch.",
                 "acceptable": "Mögliche richtige Übersetzungen:",
                 "stats": "Statistik",
+                "dueToday": "Heute fällig",
+                "done": "Erledigt",
+                "remaining": "Noch offen",
                 "success": "Erfolg",
                 "fail": "Misserfolg",
                 "srsRateTitle": "Wie sicher war das?",
@@ -462,7 +465,9 @@
                 "srsGood": "Gut",
                 "srsGoodHint": "normal planen",
                 "srsEasy": "Leicht",
-                "srsEasyHint": "größerer Abstand"
+                "srsEasyHint": "größerer Abstand",
+                "srsFinishedTitle": "Für heute erledigt",
+                "srsFinishedDesc": "Du hast alle fälligen Begriffe aus dieser Runde geübt. Wenn später neue Begriffe fällig werden, kannst du hier weitermachen."
             },
             "search": {
                 "open": "Suche",