Extended scylla-nodetool.cc to display creation_time in all task-related outputs:
- tasks_print_status: Added creation_time to time field formatting
- tasks_print_trees: Added creation_time column to task tree display
- tasks_print_stats_list: Added creation_time column to task stats list
Co-authored-by: Deexie <56607372+Deexie@users.noreply.github.com>