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>

substrate/bin/node-template/node/src/service.rs

@@ -126,7 +126,7 @@ pub fn new_partial(
 						slot_duration,
 					);
 
-				Ok((timestamp, slot))
+				Ok((slot, timestamp))
 			},
 			spawner: &task_manager.spawn_essential_handle(),
 			registry: config.prometheus_registry(),
@@ -269,7 +269,7 @@ pub fn new_full(mut config: Configuration) -> Result<TaskManager, ServiceError>
 							slot_duration,
 						);
 
-					Ok((timestamp, slot))
+					Ok((slot, timestamp))
 				},
 				force_authoring,
 				backoff_authoring_blocks,