babe: report equivocations (#6362)

* slots: create primitives crate for consensus slots

* offences: add method to check if an offence is unknown

* babe: initial equivocation reporting implementation

* babe: organize imports

* babe: working equivocation reporting

* babe: add slot number to equivocation proof

* session: move duplicate traits to session primitives

* babe: move equivocation stuff to its own file

* offences: fix test

* session: don't have primitives depend on frame_support

* babe: use opaque type for key owner proof

* babe: cleanup client equivocation reporting

* babe: cleanup equivocation code in pallet

* babe: allow sending signed equivocation reports

* node: fix compilation

* fix test compilation

* babe: return bool on check_equivocation_proof

* babe: add test for equivocation reporting

* babe: add more tests

* babe: add test for validate unsigned

* babe: take slot number in generate_key_ownership_proof API

* babe: add benchmark for equivocation proof checking

* session: add benchmark for membership proof checking

* offences: fix babe benchmark

* babe: add weights based on benchmark results

* babe: adjust weights after benchmarking on reference hardware

* babe: reorder checks in check_and_report_equivocation

substrate/frame/offences/src/lib.rs

@@ -185,6 +185,15 @@ where
 
 		Ok(())
 	}
+
+	fn is_known_offence(offenders: &[T::IdentificationTuple], time_slot: &O::TimeSlot) -> bool {
+		let any_unknown = offenders.iter().any(|offender| {
+			let report_id = Self::report_id::<O>(time_slot, offender);
+			!<Reports<T>>::contains_key(&report_id)
+		});
+
+		!any_unknown
+	}
 }
 
 impl<T: Trait> Module<T> {