Revert "FRAME: Create TransactionExtension as a replacement for SignedExtension (#2280)" (#3665)

This PR reverts #2280 which introduced `TransactionExtension` to replace
`SignedExtension`.

As a result of the discussion
[here](https://github.com/paritytech/polkadot-sdk/pull/3623#issuecomment-1986789700),
the changes will be reverted for now with plans to reintroduce the
concept in the future.

---------

Signed-off-by: georgepisaltu <george.pisaltu@parity.io>

cumulus/test/service/src/bench_utils.rs

@@ -69,7 +69,7 @@ pub fn extrinsic_set_time(client: &TestClient) -> OpaqueExtrinsic {
 
 	let timestamp = best_number as u64 * cumulus_test_runtime::MinimumPeriod::get();
 	cumulus_test_runtime::UncheckedExtrinsic {
-		preamble: sp_runtime::generic::Preamble::Bare,
+		signature: None,
 		function: cumulus_test_runtime::RuntimeCall::Timestamp(pallet_timestamp::Call::set {
 			now: timestamp,
 		}),
@@ -102,7 +102,7 @@ pub fn extrinsic_set_validation_data(
 	};
 
 	cumulus_test_runtime::UncheckedExtrinsic {
-		preamble: sp_runtime::generic::Preamble::Bare,
+		signature: None,
 		function: cumulus_test_runtime::RuntimeCall::ParachainSystem(
 			cumulus_pallet_parachain_system::Call::set_validation_data { data },
 		),

cumulus/test/service/src/lib.rs

@@ -883,7 +883,7 @@ pub fn construct_extrinsic(
 		.map(|c| c / 2)
 		.unwrap_or(2) as u64;
 	let tip = 0;
-	let tx_ext: runtime::TxExtension = (
+	let extra: runtime::SignedExtra = (
 		frame_system::CheckNonZeroSender::<runtime::Runtime>::new(),
 		frame_system::CheckSpecVersion::<runtime::Runtime>::new(),
 		frame_system::CheckGenesis::<runtime::Runtime>::new(),
@@ -895,11 +895,10 @@ pub fn construct_extrinsic(
 		frame_system::CheckWeight::<runtime::Runtime>::new(),
 		pallet_transaction_payment::ChargeTransactionPayment::<runtime::Runtime>::from(tip),
 		cumulus_primitives_storage_weight_reclaim::StorageWeightReclaim::<runtime::Runtime>::new(),
-	)
-		.into();
+	);
 	let raw_payload = runtime::SignedPayload::from_raw(
 		function.clone(),
-		tx_ext.clone(),
+		extra.clone(),
 		((), runtime::VERSION.spec_version, genesis_block, current_block_hash, (), (), (), ()),
 	);
 	let signature = raw_payload.using_encoded(|e| caller.sign(e));
@@ -907,7 +906,7 @@ pub fn construct_extrinsic(
 		function,
 		caller.public().into(),
 		runtime::Signature::Sr25519(signature),
-		tx_ext,
+		extra,
 	)
 }