refactor: Transaction-Payment module (#3816)

* Initial draft that compiles

* Extract payment stuff from balances

* Extract multiplier update stuff from system

* Some fixes.

* Update len-fee as well

* some review comments.

* Remove todo

* bump

substrate/node/testing/src/keyring.rs

@@ -72,7 +72,7 @@ pub fn signed_extra(nonce: Index, extra_fee: Balance) -> SignedExtra {
 		system::CheckEra::from(Era::mortal(256, 0)),
 		system::CheckNonce::from(nonce),
 		system::CheckWeight::new(),
-		balances::TakeFees::from(extra_fee),
+		transaction_payment::ChargeTransactionPayment::from(extra_fee),
 		Default::default(),
 	)
 }