Eliminate accessible children-changed event flood during update all

Accessible children-changed events should only be emitted when a user-
triggered action (creation of file, copying an item) causes an item to
be added.

Set container->details->is_loading (which does not seem to be used
anywhere) in caja_icon_container_request_update_all because if the
entire container is being updated, children-changed events should not
be emitted for each updated icon.

Author: joanmarie

libcaja-private/caja-icon-container.c

@@ -8025,13 +8025,15 @@ caja_icon_container_request_update_all (CajaIconContainer *container)
 
     g_return_if_fail (CAJA_IS_ICON_CONTAINER (container));
 
+    container->details->is_loading = TRUE;
     for (node = container->details->icons; node != NULL; node = node->next)
     {
         icon = node->data;
         caja_icon_container_update_icon (container, icon);
     }
 
     redo_layout (container);
+    container->details->is_loading = FALSE;
 }
 
 /**
@@ -9580,6 +9582,10 @@ caja_icon_container_accessible_icon_added_cb (CajaIconContainer *container,
     AtkObject *atk_child;
     int index;
 
+    // We don't want to emit children_changed signals during the initial load.
+    if (container->details->is_loading)
+        return;
+
     icon = g_hash_table_lookup (container->details->icon_set, icon_data);
     if (icon)
     {