There are a lot of stress tests in vmTestbase using nsk stress framework. This refactoring helps to add virtual threads testing support.

The Wicket uses plain sync/wait/notify mechanism which might cause carrier thread starvation and should be used in virtual threads.

The ManagedThread is a subclass of Thread so it couldn't be virtual thread.

Following fix changes Wicket to use locks and atomics and don't pin vthread to carrier thread while start testing.
ManagedThread is fixed to keep execution thread as the thread variable.