Moving sidebar items to computed isntead of data

Reason is that data is not inherently reactive, but computed is
When locale changes, the items will be updated correctly in computed

frontend/components/organisms/layout/TheSideBar.vue

@@ -53,8 +53,14 @@ export default {
 
   data() {
     return {
-      selected: 0,
-      items: [
+      selected: 0
+    }
+  },
+
+  computed: {
+    ...mapGetters('projects', ['loadSearchOptions']),
+    filteredItems() {
+      const items = [
         { icon: 'mdi-home', text: this.$t('projectHome.home'), link: '', adminOnly: false },
         { icon: 'mdi-database', text: this.$t('dataset.dataset'), link: 'dataset', adminOnly: true },
         { icon: 'label', text: this.$t('labels.labels'), link: 'labels', adminOnly: true },
@@ -62,13 +68,7 @@ export default {
         { icon: 'mdi-book-open-outline', text: this.$t('guideline.guideline'), link: 'guideline', adminOnly: true },
         { icon: 'mdi-chart-bar', text: this.$t('statistics.statistics'), link: 'statistics', adminOnly: true }
       ]
-    }
-  },
-
-  computed: {
-    ...mapGetters('projects', ['loadSearchOptions']),
-    filteredItems() {
-      return this.items.filter(item => this.isVisible(item))
+      return items.filter(item => this.isVisible(item))
     }
   },