If parent_info argument of compaction_manager::perform_compaction
is std::nullopt, then created compaction executor isn't tracked by task
manager. Currently, all compaction operations should by visible in task
manager.
Modify split methods to keep split executor in task manager. Get rid of
the option to bypass task manager.
Closesscylladb/scylladb#19995
* github.com:scylladb/scylladb:
compaction: replace optional<task_info> with task_info param
compaction: keep split executor in task manager