feat(vocab): add language and course dictionary endpoints and UI components

- Implemented `getLanguageDictionary` and `getCourseDictionary` methods in the VocabService to retrieve vocabulary entries filtered by search terms.
- Updated VocabController and vocabRouter to include new routes for accessing language and course dictionaries.
- Enhanced frontend components to navigate to the new dictionary views, including buttons in VocabCourseView and VocabLanguageView.
- Added localization entries for the dictionary feature in multiple languages, ensuring a consistent user experience across the platform.

frontend/src/i18n/locales/es/general.json

@@ -148,6 +148,7 @@
             "subscribeLanguage": "Suscribirse al idioma",
             "language": "Idioma",
             "chapter": "Capítulo",
+            "vocabDictionary": "Diccionario",
             "courses": "Cursos",
             "course": "Curso",
             "lesson": "Lección",

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

@@ -466,6 +466,19 @@
                 "noResults": "Sin resultados.",
                 "error": "La búsqueda ha fallado."
             },
+            "dictionary": {
+                "open": "Diccionario",
+                "kicker": "Consulta",
+                "intro": "Todos los términos de tus capítulos. Un solo campo filtra en ambos idiomas por coincidencias parciales.",
+                "searchLabel": "Búsqueda (ambos idiomas)",
+                "searchPlaceholder": "Parte de una palabra en cualquier idioma…",
+                "empty": "Sin entradas.",
+                "loadError": "No se pudo cargar el diccionario.",
+                "notFound": "Sin acceso o no encontrado.",
+                "languageTitle": "Diccionario: {name}",
+                "courseTitle": "Diccionario del curso: {name}",
+                "courseLearningColumn": "Idioma de aprendizaje (curso)"
+            },
             "courses": {
                 "title": "Cursos de idiomas",
                 "create": "Crear curso",