rtos/lists: add double_list_iterator
rtos/lists: add double_list_iterator

- remove wrong begin()/end() from static_double_list
- add begin()/end() to waiting_threads_list
- make waiting_threads_list::resume_one() bool, to simplify resume_all()
- make waiting_thread_node::thread_ a pointer, to be used in iterator

micro-os-plus/cmsis-plus,micro-os-plus/cmsis-plus,micro-os-plus/cmsis-plus,micro-os-plus/cmsis-plus