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/cli/src/service.rs

@@ -223,7 +223,7 @@ pub fn new_partial(
 			let uncles =
 				sp_authorship::InherentDataProvider::<<Block as BlockT>::Header>::check_inherents();
 
-			Ok((timestamp, slot, uncles))
+			Ok((slot, timestamp, uncles))
 		},
 		&task_manager.spawn_essential_handle(),
 		config.prometheus_registry(),
@@ -453,7 +453,7 @@ pub fn new_full_base(
 							&parent,
 						)?;
 
-					Ok((timestamp, slot, uncles, storage_proof))
+					Ok((slot, timestamp, uncles, storage_proof))
 				}
 			},
 			force_authoring,