Revisit tasks logging

Before NX3 Scheduler (legacy scheduler) there was a lot (was maybe even noisy) logging about tasks started, stoppped ,etc...

With new scheduler we got to the "opposite end of the horse", silence. Scheduler uses INFO logging very sparingly.

Tinker about, do we need at least some INFO logs about tasks, and if yes what? State transition?

Note: This is about logging only, as feeds are preserved and should be available with full content as before.