swaybar: add status_edge_padding command

This adds the bar subcommand `status_edge_padding <padding>` to set the
padding used when the status line is on the right edge of the bar.

swaybar/config.c

@@ -38,6 +38,7 @@ struct swaybar_config *init_config(void) {
 	config->bindings = create_list();
 	wl_list_init(&config->outputs);
 	config->status_padding = 1;
+	config->status_edge_padding = 3;
 
 	/* height */
 	config->height = 0;