Return also labels from <dougal-context-menu/>.

Keeping in mind that the input model is a tree and labels
may be at any level in the tree, not just in the leaves.

lib/www/client/source/src/components/context-menu.vue

@@ -21,6 +21,7 @@
         <dougal-context-menu  v-if="item.items"
           :value="showSubmenu"
           :items="item.items"
+          :labels="labels.concat(item.labels||[])"
           @input="selected"
           submenu>
           <template v-slot:activator="{ on, attrs }">
@@ -56,6 +57,7 @@ export default {
 
   props: {
     value: { type: [ MouseEvent, Object, Boolean ] },
+    labels: { type: [ Array ], default: () => [] },
     absolute: { type: Boolean, default: false },
     submenu: { type: Boolean, default: false },
     items: { type: Array, default: () => [] }
@@ -97,7 +99,12 @@ export default {
 
     selected (item) {
       this.show = false;
-      this.$emit('input', item);
+      if (typeof item === 'object' && item !== null) {
+        const labels = this.labels.concat(item.labels??[]);
+        this.$emit('input', {...item, labels});
+      } else {
+        this.$emit('input', item);
+      }
     }
 
   }