fix: provide with can_paste_component in serializers (#34521)

cms/djangoapps/contentstore/rest_api/v1/serializers/vertical_block.py

@@ -152,3 +152,4 @@ class VerticalContainerSerializer(serializers.Serializer):
 
     children = ChildVerticalContainerSerializer(many=True)
     is_published = serializers.BooleanField()
+    can_paste_component = serializers.BooleanField()

cms/djangoapps/contentstore/rest_api/v1/views/tests/test_vertical_block.py

@@ -153,6 +153,7 @@ class ContainerVerticalViewTest(BaseXBlockContainer):
         self.assertEqual(response.status_code, status.HTTP_200_OK)
         self.assertEqual(len(response.data["children"]), 2)
         self.assertFalse(response.data["is_published"])
+        self.assertTrue(response.data["can_paste_component"])
 
     def test_xblock_is_published(self):
         """