thread: implement some properties

Make helper method to parse thread properties and add 2 new properties
to control name and stack-size of the thread.
Use properties when creating threads with the default utils.
Use the default thread utils instead of pthread_create so that the
properties are used.

src/pipewire/private.h

@@ -1290,6 +1290,8 @@ void pw_settings_clean(struct pw_context *context);
 
 void pw_impl_module_schedule_destroy(struct pw_impl_module *module);
 
+pthread_attr_t *pw_thread_fill_attr(const struct spa_dict *props, pthread_attr_t *attr);
+
 /** \endcond */
 
 #ifdef __cplusplus