Collection of enhancement for staking/phragmen. (#5534)

* Collection of enhancement for staking phragmen.

* Ditch signed extension

* Fix build

* Update frame/staking/src/lib.rs

Co-Authored-By: thiolliere <gui.thiolliere@gmail.com>

* Update frame/staking/src/tests.rs

Co-Authored-By: thiolliere <gui.thiolliere@gmail.com>

* Fix reward limits

* Disallow payout_stakers

* Remove unused import

Co-authored-by: thiolliere <gui.thiolliere@gmail.com>

substrate/bin/utils/subkey/src/main.rs

@@ -690,7 +690,6 @@ fn create_extrinsic<C: Crypto>(
 			frame_system::CheckWeight::<Runtime>::new(),
 			pallet_transaction_payment::ChargeTransactionPayment::<Runtime>::from(f),
 			Default::default(),
-			Default::default(),
 		)
 	};
 	let raw_payload = SignedPayload::from_raw(
@@ -704,7 +703,6 @@ fn create_extrinsic<C: Crypto>(
 			(),
 			(),
 			(),
-			(),
 		),
 	);
 	let signature = raw_payload.using_encoded(|payload| signer.sign(payload)).into_runtime();