Fix optional chaining for frontRowActions in MoreTable

Updated the conditional check for `frontRowActions` to use optional chaining, preventing potential runtime errors when the property is undefined or null. This ensures more robust and error-proof behavior for row action rendering.

src/components/shared/MoreTable.vue

@@ -305,7 +305,7 @@ Licensed under the Elastic License 2.0. */
       @row-click="onRowClick($event)"
     >
       <Column
-        v-if="frontRowActions.length"
+        v-if="frontRowActions?.length"
         key="actions"
         class="row-actions"
         :frozen="true"