swaybar: add status_padding command

Adds the bar subcommand `status_padding <padding>` which allows setting
the padding used for swaybar. If `status_padding` is set to `0`, blocks
will be able to take up the full height of the bar.

swaybar/config.c

@@ -37,6 +37,7 @@ struct swaybar_config *init_config(void) {
 	config->workspace_buttons = true;
 	config->bindings = create_list();
 	wl_list_init(&config->outputs);
+	config->status_padding = 1;
 
 	/* height */
 	config->height = 0;