[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>

bridges/primitives/runtime/src/lib.rs

@@ -23,7 +23,6 @@ use frame_support::{
 	pallet_prelude::DispatchResult, weights::Weight, PalletError, StorageHasher, StorageValue,
 };
 use frame_system::RawOrigin;
-use log;
 use scale_info::TypeInfo;
 use serde::{Deserialize, Serialize};
 use sp_core::storage::StorageKey;
@@ -98,6 +97,9 @@ pub const BRIDGE_HUB_ROCOCO_CHAIN_ID: ChainId = *b"bhro";
 /// BridgeHubWococo chain id.
 pub const BRIDGE_HUB_WOCOCO_CHAIN_ID: ChainId = *b"bhwo";
 
+/// BridgeHubWestend chain id.
+pub const BRIDGE_HUB_WESTEND_CHAIN_ID: ChainId = *b"bhwd";
+
 /// BridgeHubKusama chain id.
 pub const BRIDGE_HUB_KUSAMA_CHAIN_ID: ChainId = *b"bhks";