Xcm emulator nits (#1649)

# Desription

## Summary 

This PR introduces several nits and tweaks to xcm emulator tests for
system parachains.

## Explanation

**Deduplicate `XcmPallet::send(` with root origin code**
- Introduced `send_transact_to_parachain` which could be easily reuse
for scenarios like _governance call from relay chain to parachain_.

**Refactor `send_transact_sudo_from_relay_to_system_para_works`**
- Test covered just one use-case which was moved to the
`do_force_create_asset_from_relay_to_system_para`, so now we can extend
this test with more _governance-like_ senarios.
- Renamed to
`send_transact_as_superuser_from_relay_to_system_para_works`.

**Remove `send_transact_native_from_relay_to_system_para_fails` test**
- This test and/or description is kind of misleading, because system
paras support Native from relay chain by `RelayChainAsNative` with
correct xcm origin.
- It tested only sending on relay chain which should go directly to the
relay chain unit-tests (does not even need to be in xcm emulator level).

## Future directions

Check restructure parachains integration tests
[issue](https://github.com/paritytech/polkadot-sdk/issues/1389) and [PR
with more TODOs](https://github.com/paritytech/polkadot-sdk/pull/1693).

---------

Co-authored-by: Ignacio Palacios <ignacio.palacios.santos@gmail.com>

cumulus/parachains/integration-tests/emulated/assets/asset-hub-westend/src/tests/reserve_transfer.rs

@@ -349,6 +349,7 @@ fn limited_reserve_transfer_asset_from_system_para_to_para() {
 		ASSET_MIN_BALANCE,
 		true,
 		AssetHubWestendSender::get(),
+		Some(Weight::from_parts(1_019_445_000, 200_000)),
 		ASSET_MIN_BALANCE * 1000000,
 	);
 
@@ -384,6 +385,7 @@ fn reserve_transfer_asset_from_system_para_to_para() {
 		ASSET_MIN_BALANCE,
 		true,
 		AssetHubWestendSender::get(),
+		Some(Weight::from_parts(1_019_445_000, 200_000)),
 		ASSET_MIN_BALANCE * 1000000,
 	);
 

cumulus/parachains/integration-tests/emulated/assets/asset-hub-westend/src/tests/send.rs

@@ -16,52 +16,16 @@
 use crate::*;
 
 /// Relay Chain should be able to execute `Transact` instructions in System Parachain
-/// when `OriginKind::Superuser` and signer is `sudo`
+/// when `OriginKind::Superuser`.
 #[test]
-fn send_transact_sudo_from_relay_to_system_para_works() {
-	// Init tests variables
-	let root_origin = <Westend as Chain>::RuntimeOrigin::root();
-	let system_para_destination = Westend::child_location_of(AssetHubWestend::para_id()).into();
-	let asset_owner: AccountId = AssetHubWestendSender::get().into();
-	let xcm = AssetHubWestend::force_create_asset_xcm(
-		OriginKind::Superuser,
+fn send_transact_as_superuser_from_relay_to_system_para_works() {
+	AssetHubWestend::force_create_asset_from_relay_as_root(
 		ASSET_ID,
-		asset_owner.clone(),
+		ASSET_MIN_BALANCE,
 		true,
-		1000,
-	);
-	// Send XCM message from Relay Chain
-	Westend::execute_with(|| {
-		assert_ok!(<Westend as WestendPallet>::XcmPallet::send(
-			root_origin,
-			bx!(system_para_destination),
-			bx!(xcm),
-		));
-
-		Westend::assert_xcm_pallet_sent();
-	});
-
-	// Receive XCM message in Assets Parachain
-	AssetHubWestend::execute_with(|| {
-		type RuntimeEvent = <AssetHubWestend as Chain>::RuntimeEvent;
-
-		AssetHubWestend::assert_dmp_queue_complete(Some(Weight::from_parts(
-			1_019_445_000,
-			200_000,
-		)));
-
-		assert_expected_events!(
-			AssetHubWestend,
-			vec![
-				RuntimeEvent::Assets(pallet_assets::Event::ForceCreated { asset_id, owner }) => {
-					asset_id: *asset_id == ASSET_ID,
-					owner: *owner == asset_owner,
-				},
-			]
-		);
-
-		assert!(<AssetHubWestend as AssetHubWestendPallet>::Assets::asset_exists(ASSET_ID));
-	});
+		AssetHubWestendSender::get().into(),
+		Some(Weight::from_parts(1_019_445_000, 200_000)),
+	)
 }
 
 /// Parachain should be able to send XCM paying its fee with sufficient asset
@@ -78,6 +42,7 @@ fn send_xcm_from_para_to_system_para_paying_fee_with_assets_works() {
 		ASSET_MIN_BALANCE,
 		true,
 		para_sovereign_account.clone(),
+		Some(Weight::from_parts(1_019_445_000, 200_000)),
 		ASSET_MIN_BALANCE * 1000000000,
 	);
 

cumulus/parachains/integration-tests/emulated/assets/asset-hub-westend/src/tests/set_xcm_versions.rs

@@ -47,32 +47,22 @@ fn relay_sets_system_para_xcm_supported_version() {
 #[test]
 fn system_para_sets_relay_xcm_supported_version() {
 	// Init test variables
-	let sudo_origin = <Westend as Chain>::RuntimeOrigin::root();
 	let parent_location = AssetHubWestend::parent_location();
-	let system_para_destination: VersionedMultiLocation =
-		Westend::child_location_of(AssetHubWestend::para_id()).into();
-	let call = <AssetHubWestend as Chain>::RuntimeCall::PolkadotXcm(pallet_xcm::Call::<
-		<AssetHubWestend as Chain>::Runtime,
-	>::force_xcm_version {
-		location: bx!(parent_location),
-		version: XCM_V3,
-	})
-	.encode()
-	.into();
-	let origin_kind = OriginKind::Superuser;
+	let force_xcm_version_call =
+		<AssetHubWestend as Chain>::RuntimeCall::PolkadotXcm(pallet_xcm::Call::<
+			<AssetHubWestend as Chain>::Runtime,
+		>::force_xcm_version {
+			location: bx!(parent_location),
+			version: XCM_V3,
+		})
+		.encode()
+		.into();
 
-	let xcm = xcm_transact_unpaid_execution(call, origin_kind);
-
-	// System Parachain sets supported version for Relay Chain throught it
-	Westend::execute_with(|| {
-		assert_ok!(<Westend as WestendPallet>::XcmPallet::send(
-			sudo_origin,
-			bx!(system_para_destination),
-			bx!(xcm),
-		));
-
-		Westend::assert_xcm_pallet_sent();
-	});
+	// System Parachain sets supported version for Relay Chain through it
+	Westend::send_unpaid_transact_to_parachain_as_root(
+		AssetHubWestend::para_id(),
+		force_xcm_version_call,
+	);
 
 	// System Parachain receive the XCM message
 	AssetHubWestend::execute_with(|| {