xcm-emulator: add Rococo<>Westend bridge and add tests for assets transfers over the bridge (#2251)

- switch from Rococo<>Wococo to Rococo<>Westend bridge
- add bidirectional simple tests
- remove Wococo chains from xcm-emulator
- added tests for assets transfers over Rococo<>Westend bridge 

fixes https://github.com/paritytech/parity-bridges-common/issues/2405

cumulus/parachains/integration-tests/emulated/networks/rococo-westend-system/Cargo.toml

@@ -0,0 +1,18 @@
+[package]
+name = "rococo-westend-system-emulated-network"
+version = "0.0.0"
+authors.workspace = true
+edition.workspace = true
+license = "Apache-2.0"
+description = "Rococo<>Westend emulated bridged network"
+publish = false
+
+[dependencies]
+# Cumulus
+emulated-integration-tests-common = { path = "../../common", default-features = false }
+rococo-emulated-chain = { path = "../../chains/relays/rococo" }
+westend-emulated-chain = { path = "../../chains/relays/westend" }
+asset-hub-rococo-emulated-chain = { path = "../../chains/parachains/assets/asset-hub-rococo" }
+asset-hub-westend-emulated-chain = { path = "../../chains/parachains/assets/asset-hub-westend" }
+bridge-hub-rococo-emulated-chain = { path = "../../chains/parachains/bridges/bridge-hub-rococo" }
+bridge-hub-westend-emulated-chain = { path = "../../chains/parachains/bridges/bridge-hub-westend" }

cumulus/parachains/integration-tests/emulated/networks/rococo-westend-system/src/lib.rs

@@ -0,0 +1,96 @@
+// Copyright (C) Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: Apache-2.0
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+pub use asset_hub_rococo_emulated_chain;
+pub use asset_hub_westend_emulated_chain;
+pub use bridge_hub_rococo_emulated_chain;
+pub use bridge_hub_westend_emulated_chain;
+pub use rococo_emulated_chain;
+pub use westend_emulated_chain;
+
+use asset_hub_rococo_emulated_chain::AssetHubRococo;
+use asset_hub_westend_emulated_chain::AssetHubWestend;
+use bridge_hub_rococo_emulated_chain::BridgeHubRococo;
+use bridge_hub_westend_emulated_chain::BridgeHubWestend;
+use rococo_emulated_chain::Rococo;
+use westend_emulated_chain::Westend;
+
+// Cumulus
+use emulated_integration_tests_common::{
+	accounts::{ALICE, BOB},
+	impls::{BridgeHubMessageHandler, BridgeMessagesInstance1, BridgeMessagesInstance3},
+	xcm_emulator::{
+		decl_test_bridges, decl_test_networks, decl_test_sender_receiver_accounts_parameter_types,
+		Chain,
+	},
+};
+
+decl_test_networks! {
+	pub struct RococoMockNet {
+		relay_chain = Rococo,
+		parachains = vec![
+			AssetHubRococo,
+			BridgeHubRococo,
+		],
+		bridge = RococoWestendMockBridge
+
+	},
+	pub struct WestendMockNet {
+		relay_chain = Westend,
+		parachains = vec![
+			AssetHubWestend,
+			BridgeHubWestend,
+		],
+		bridge = WestendRococoMockBridge
+	},
+}
+
+decl_test_bridges! {
+	pub struct RococoWestendMockBridge {
+		source = BridgeHubRococoPara,
+		target = BridgeHubWestendPara,
+		handler = RococoWestendMessageHandler
+	},
+	pub struct WestendRococoMockBridge {
+		source = BridgeHubWestendPara,
+		target = BridgeHubRococoPara,
+		handler = WestendRococoMessageHandler
+	}
+}
+
+type BridgeHubRococoRuntime = <BridgeHubRococoPara as Chain>::Runtime;
+type BridgeHubWestendRuntime = <BridgeHubWestendPara as Chain>::Runtime;
+
+pub type RococoWestendMessageHandler = BridgeHubMessageHandler<
+	BridgeHubRococoRuntime,
+	BridgeMessagesInstance3,
+	BridgeHubWestendRuntime,
+	BridgeMessagesInstance1,
+>;
+pub type WestendRococoMessageHandler = BridgeHubMessageHandler<
+	BridgeHubWestendRuntime,
+	BridgeMessagesInstance1,
+	BridgeHubRococoRuntime,
+	BridgeMessagesInstance3,
+>;
+
+decl_test_sender_receiver_accounts_parameter_types! {
+	RococoRelay { sender: ALICE, receiver: BOB },
+	AssetHubRococoPara { sender: ALICE, receiver: BOB },
+	BridgeHubRococoPara { sender: ALICE, receiver: BOB },
+	WestendRelay { sender: ALICE, receiver: BOB },
+	AssetHubWestendPara { sender: ALICE, receiver: BOB },
+	BridgeHubWestendPara { sender: ALICE, receiver: BOB }
+}