Independence of Slot-based algorithms from system Timestamp (#12224)

* Remove timestamp from SlotInfo

* Expose as millis instead of secs

* Nits

* Fix test after field removal

* Yet another test fix

* On the fly timestamp computation

* Removed slot timestamp from logs

* Removed reference to timestamp from slots subsystem

* Slot based algorithm tests do not require timstamp inherent anymore

* Remove junk files

* Further tests cleanup

* Trigger pipeline

* Apply code suggestions

* Trigger pipeline

Co-authored-by: André Silva <andrerfosilva@gmail.com>