[testnet] Add AssetHubRococo <-> AssetHubWestend asset bridging support (#1967)

## Summary

Asset bridging support for AssetHub**Rococo** <-> AssetHub**Wococo** was
added [here](https://github.com/paritytech/polkadot-sdk/pull/1215), so
now we aim to bridge AssetHub**Rococo** and AssetHub**Westend**. (And
perhaps retire AssetHubWococo and the Wococo chains).

## Solution

**bridge-hub-westend-runtime**
- added new runtime as a copy of `bridge-hub-rococo-runtime`
- added support for bridging to `BridgeHubRococo`
- added tests and benchmarks

**bridge-hub-rococo-runtime**
- added support for bridging to `BridgeHubWestend`
- added tests and benchmarks
- internal refactoring by splitting bridge configuration per network,
e.g., `bridge_to_whatevernetwork_config.rs`.

**asset-hub-rococo-runtime**
- added support for asset bridging to `AssetHubWestend` (allows to
receive only WNDs)
- added new xcm router for `Westend`
- added tests and benchmarks

**asset-hub-westend-runtime**
- added support for asset bridging to `AssetHubRococo` (allows to
receive only ROCs)
- added new xcm router for `Rococo`
- added tests and benchmarks

## Deployment

All changes will be deployed as a part of
https://github.com/paritytech/polkadot-sdk/issues/1988.

## TODO

- [x] benchmarks for all pallet instances
- [x] integration tests
- [x] local run scripts


Relates to:
https://github.com/paritytech/parity-bridges-common/issues/2602
Relates to: https://github.com/paritytech/polkadot-sdk/issues/1988

---------

Co-authored-by: command-bot <>
Co-authored-by: Adrian Catangiu <adrian@parity.io>
Co-authored-by: joe petrowski <25483142+joepetrowski@users.noreply.github.com>

cumulus/parachains/integration-tests/emulated/common/src/constants.rs

@@ -669,16 +669,14 @@ pub mod bridge_hub_rococo {
 				owner: Some(get_account_id_from_seed::<sr25519::Public>(accounts::BOB)),
 				..Default::default()
 			},
-			bridge_wococo_to_rococo_messages:
-				bridge_hub_rococo_runtime::BridgeWococoToRococoMessagesConfig {
-					owner: Some(get_account_id_from_seed::<sr25519::Public>(accounts::BOB)),
-					..Default::default()
-				},
-			bridge_rococo_to_wococo_messages:
-				bridge_hub_rococo_runtime::BridgeRococoToWococoMessagesConfig {
-					owner: Some(get_account_id_from_seed::<sr25519::Public>(accounts::BOB)),
-					..Default::default()
-				},
+			bridge_rococo_messages: bridge_hub_rococo_runtime::BridgeRococoMessagesConfig {
+				owner: Some(get_account_id_from_seed::<sr25519::Public>(accounts::BOB)),
+				..Default::default()
+			},
+			bridge_wococo_messages: bridge_hub_rococo_runtime::BridgeWococoMessagesConfig {
+				owner: Some(get_account_id_from_seed::<sr25519::Public>(accounts::BOB)),
+				..Default::default()
+			},
 			..Default::default()
 		};