Add various gtk list models

This is an exact copy from GTK4.
as grabbed by chattys commit 1ed5084fb965908e3ee0304781b0de06479c869b

Slightly adapted for Calls.

Based on GTKs 01bd4cc4e18a1ea697fe61791ba710d0d55e8290

src/gtklistmodels/gtkcustomsorter.h

@@ -0,0 +1,50 @@
+/*
+ * Copyright © 2019 Matthias Clasen
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Matthias Clasen <mclasen@redhat.com>
+ */
+
+#ifndef __GTK_CUSTOM_SORTER_H__
+#define __GTK_CUSTOM_SORTER_H__
+
+#define GTK_COMPILATION
+#if !defined (__GTK_H_INSIDE__) && !defined (GTK_COMPILATION)
+#error "Only <gtk/gtk.h> can be included directly."
+#endif
+
+/* #include <gtk/gtkexpression.h> */
+#include "gtksorter.h"
+
+G_BEGIN_DECLS
+
+#define GTK_TYPE_CUSTOM_SORTER             (gtk_custom_sorter_get_type ())
+GDK_AVAILABLE_IN_ALL
+G_DECLARE_FINAL_TYPE (GtkCustomSorter, gtk_custom_sorter, GTK, CUSTOM_SORTER, GtkSorter)
+
+GDK_AVAILABLE_IN_ALL
+GtkSorter *             gtk_custom_sorter_new                   (GCompareDataFunc        sort_func,
+                                                                 gpointer                user_data,
+                                                                 GDestroyNotify          user_destroy);
+
+GDK_AVAILABLE_IN_ALL
+void                    gtk_custom_sorter_set_sort_func         (GtkCustomSorter        *self,
+                                                                 GCompareDataFunc        sort_func,
+                                                                 gpointer                user_data,
+                                                                 GDestroyNotify          user_destroy);
+
+G_END_DECLS
+
+#endif /* __GTK_CUSTOM_SORTER_H__ */