For compaction_task_executors, unlike for all other task manager
tasks, run method does not embrace operations performed in a scope
of a task, but only waits until shared_future connected with
the operations is resolved.
Apart from breaking task manager task conventions, such a run method
must consider all corner cases, not to break task manager or
compaction manager functionality.
To fix existing and prevent further bugs related to task manager
and compaction manager coexistence, call perform_task inside
run method and wait for it in a standard way.
Executors that are not going to be reflected in task manager run call
perform_task the old way.