Use host_id in a children list of a task in task manager to indicate a node on which the child was created. Move TASKS_CHILDREN_REQUEST to IDL. Send it by host_id. Fixes: https://github.com/scylladb/scylladb/issues/22284. Ip to host_id transition; backport isn't needed. Closes scylladb/scylladb#22487 * github.com:scylladb/scylladb: tasks: drop task_manager::config::broadcast_address as it's unused tasks: replace ip with host_id in task_identity api: task_manager: pass gossiper to api::set_task_manager tasks: keep host_id in task_manager tasks: move tasks_get_children to IDL