widget: Add name to widget paths

This changes widget paths for widgets with a CSS name to return that CSS
name, now that we have added API for it.
This means that style properties are now matches using the CSS name.

Also fix the theme to use the correct name when matching style properties.

gtk/gtkwidget.c

@@ -16223,6 +16223,7 @@ gtk_widget_path_append_for_widget (GtkWidgetPath *path,
   g_return_val_if_fail (GTK_IS_WIDGET (widget), 0);
 
   pos = gtk_widget_path_append_type (path, gtk_css_node_get_widget_type (widget->priv->cssnode));
+  gtk_widget_path_iter_set_object_name (path, pos, gtk_css_node_get_name (widget->priv->cssnode));
 
   if (widget->priv->name)
     gtk_widget_path_iter_set_name (path, pos, widget->priv->name);

gtk/theme/Adwaita/_common.scss

@@ -1549,7 +1549,7 @@ column-header.button.dnd { // for treeview-like derive widgets
  * Tabs          *
  *****************/
 
-GtkNotebook {
+notebook {
   -GtkNotebook-initial-gap: 10;
   -GtkNotebook-arrow-spacing: 5;
   -GtkNotebook-tab-curvature: 0;
@@ -1557,9 +1557,7 @@ GtkNotebook {
   -GtkNotebook-has-tab-gap: false;
   -GtkWidget-focus-padding: 0;
   -GtkWidget-focus-line-width: 0;
-}
 
-notebook {
   // Through me you go to the grief wracked city;
   // Through me you go to everlasting pain;
   // Through me you go a pass among lost souls.

gtk/theme/HighContrast/_common.scss

@@ -1226,7 +1226,7 @@ GtkTreeView.view.progressbar { //Progressbar in treeview cells
  * Tabs          *
  *****************/
 
-GtkNotebook {
+notebook {
   -GtkNotebook-initial-gap: 10;
   -GtkNotebook-arrow-spacing: 5;
   -GtkNotebook-tab-curvature: 0;
@@ -1234,9 +1234,7 @@ GtkNotebook {
   -GtkNotebook-has-tab-gap: false;
   -GtkWidget-focus-padding: 0;
   -GtkWidget-focus-line-width: 0;
-}
 
-notebook {
   // Through me you go to the grief wracked city;
   // Through me you go to everlasting pain;
   // Through me you go a pass among lost souls.