Rename frame_create and frame_set_child_size with a window_ prefix

This is to avoid a collision with an actual frame structure.

Signed-off-by: Jason Ekstrand <jason@jlekstrand.net>
diff --git a/clients/editor.c b/clients/editor.c
index 12650f3..6e38426 100644
--- a/clients/editor.c
+++ b/clients/editor.c
@@ -1221,7 +1221,7 @@
 	display_set_global_handler(editor.display, global_handler);
 
 	editor.window = window_create(editor.display);
-	editor.widget = frame_create(editor.window, &editor);
+	editor.widget = window_frame_create(editor.window, &editor);
 
 	editor.entry = text_entry_create(&editor, "Entry");
 	editor.entry->click_to_show = click_to_show;