III-6978: add theme preview with translations

Author: alduya

src/i18n/de.json

@@ -1421,6 +1421,7 @@
     "labels": {
       "title": "Titel",
       "type": "Typ",
+      "theme": "Thema",
       "labels": "Labels",
       "description": "Beschreibung",
       "location": "Wo",
@@ -1438,6 +1439,7 @@
     },
     "empty_value": {
       "description": "Keine Beschreibung",
+      "theme": "Kein Thema",
       "organiser": "Keine Organisationsinformationen",
       "price": "Keine Preisinformation",
       "booking": "Keine Reservierungsinformationen",

src/i18n/fr.json

@@ -1420,6 +1420,7 @@
     "labels": {
       "title": "Titre",
       "type": "Type",
+      "theme": "Thème",
       "labels": "Étiquettes",
       "description": "Description",
       "location": "Où",
@@ -1437,6 +1438,7 @@
     },
     "empty_value": {
       "description": "Aucune description",
+      "theme": "Aucun thème",
       "organiser": "Aucune information sur l'organisation",
       "price": "Pas d'information du prix",
       "booking": "Aucune information sur la réservation",

src/i18n/nl.json

@@ -1477,6 +1477,7 @@
     "labels": {
       "title": "Titel",
       "type": "Type",
+      "theme": "Thema",
       "labels": "Labels",
       "description": "Beschrijving",
       "location": "Waar",
@@ -1494,6 +1495,7 @@
     },
     "empty_value": {
       "description": "Geen beschrijving",
+      "theme": "Geen thema",
       "organiser": "Geen organisatie-informatie",
       "price": "Geen prijsinformatie",
       "booking": "Geen reservatie-informatie",

src/pages/events/[eventId]/preview/Preview.tsx

@@ -69,6 +69,7 @@ const Preview = () => {
   );
 
   const typeTerm = terms.find((term) => term.domain === 'eventtype');
+  const themeTerm = terms.find((term) => term.domain === 'theme');
 
   const description = getLanguageObjectOrFallback<string>(
     offer.description,
@@ -271,6 +272,14 @@ const Preview = () => {
   const tableData = [
     { field: t('preview.labels.title'), value: title },
     { field: t('preview.labels.type'), value: typeTerm.label },
+    {
+      field: t('preview.labels.theme'),
+      value: themeTerm ? (
+        themeTerm.label
+      ) : (
+        <EmptyValue>{t('preview.empty_value.theme')}</EmptyValue>
+      ),
+    },
     {
       field: t('preview.labels.labels'),
       value: (