Upgrade authorship pallet to Frame-v2 (#8663)

* first commit

* get to compile

* fix deprecated grandpa

* formatting

* module to pallet

* add authorship pallet to mocks

* Fix upgrade of storage.

Co-authored-by: Xiliang Chen <xlchen1291@gmail.com>

* trigger CI

* put back doc

Co-authored-by: Guillaume Thiolliere <gui.thiolliere@gmail.com>
Co-authored-by: Xiliang Chen <xlchen1291@gmail.com>

substrate/frame/babe/src/equivocation.rs

@@ -175,7 +175,7 @@ where
 	}
 
 	fn block_author() -> Option<T::AccountId> {
-		Some(<pallet_authorship::Module<T>>::author())
+		Some(<pallet_authorship::Pallet<T>>::author())
 	}
 }