remove pipewire/private.h includes when possible

In many places this is not needed.
Expose pw_impl_node_set_param() for adapter.

src/modules/module-avb/internal.h

@@ -45,7 +45,6 @@ struct impl {
 	unsigned do_disconnect:1;
 
 	struct pw_properties *props;
-	struct pw_work_queue *work_queue;
 
 	struct spa_list servers;
 };