[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/runtimes/bridge-hubs/bridge-hub-rococo/Cargo.toml

@@ -75,8 +75,10 @@ parachains-common = { path = "../../../common", default-features = false }
 
 # Bridges
 bp-asset-hub-rococo = { path = "../../../../../bridges/primitives/chain-asset-hub-rococo", default-features = false }
+bp-asset-hub-westend = { path = "../../../../../bridges/primitives/chain-asset-hub-westend", default-features = false }
 bp-asset-hub-wococo = { path = "../../../../../bridges/primitives/chain-asset-hub-wococo", default-features = false }
 bp-bridge-hub-rococo = { path = "../../../../../bridges/primitives/chain-bridge-hub-rococo", default-features = false }
+bp-bridge-hub-westend = { path = "../../../../../bridges/primitives/chain-bridge-hub-westend", default-features = false }
 bp-bridge-hub-wococo = { path = "../../../../../bridges/primitives/chain-bridge-hub-wococo", default-features = false }
 bp-header-chain = { path = "../../../../../bridges/primitives/header-chain", default-features = false }
 bp-messages = { path = "../../../../../bridges/primitives/messages", default-features = false }
@@ -85,6 +87,7 @@ bp-polkadot-core = { path = "../../../../../bridges/primitives/polkadot-core", d
 bp-relayers = { path = "../../../../../bridges/primitives/relayers", default-features = false }
 bp-runtime = { path = "../../../../../bridges/primitives/runtime", default-features = false }
 bp-rococo = { path = "../../../../../bridges/primitives/chain-rococo", default-features = false }
+bp-westend = { path = "../../../../../bridges/primitives/chain-westend", default-features = false }
 bp-wococo = { path = "../../../../../bridges/primitives/chain-wococo", default-features = false }
 pallet-bridge-grandpa = { path = "../../../../../bridges/modules/grandpa", default-features = false }
 pallet-bridge-messages = { path = "../../../../../bridges/modules/messages", default-features = false }
@@ -102,8 +105,10 @@ sp-keyring = { path = "../../../../../substrate/primitives/keyring" }
 default = [ "std" ]
 std = [
 	"bp-asset-hub-rococo/std",
+	"bp-asset-hub-westend/std",
 	"bp-asset-hub-wococo/std",
 	"bp-bridge-hub-rococo/std",
+	"bp-bridge-hub-westend/std",
 	"bp-bridge-hub-wococo/std",
 	"bp-header-chain/std",
 	"bp-messages/std",
@@ -112,6 +117,7 @@ std = [
 	"bp-relayers/std",
 	"bp-rococo/std",
 	"bp-runtime/std",
+	"bp-westend/std",
 	"bp-wococo/std",
 	"bridge-runtime-common/std",
 	"codec/std",