[xcm-emulator] Chains generic over Network & Integration tests restructure (#2092)

Closes:
- #1383 
- Declared chains can be now be imported and reused in a different
crate.
- Chain declaration are now generic over a generic type `N` (the
Network)
- #1389
- Solved #1383, chains and networks declarations can be restructure to
avoid having to compile all chains when running integrations tests where
are not needed.
- Chains are now declared on its own crate (removed from
`integration-tests-common`)
- Networks are now declared on its own crate (removed from
`integration-tests-common`)
    - Integration tests will import only the relevant Network crate
- `integration-tests-common` is renamed to
`emulated-integration-tests-common`

All this is necessary to be able to implement what is described here:
https://github.com/paritytech/roadmap/issues/56#issuecomment-1777010553

---------

Co-authored-by: command-bot <>

cumulus/parachains/integration-tests/emulated/tests/bridges/bridge-hub-westend/Cargo.toml

@@ -0,0 +1,33 @@
+[package]
+name = "bridge-hub-westend-integration-tests"
+version = "1.0.0"
+authors.workspace = true
+edition.workspace = true
+license = "Apache-2.0"
+description = "Bridge Hub Westend runtime integration tests with xcm-emulator"
+publish = false
+
+[dependencies]
+codec = { package = "parity-scale-codec", version = "3.4.0", default-features = false }
+
+# Substrate
+frame-support = { path = "../../../../../../../substrate/frame/support", default-features = false}
+pallet-message-queue = { path = "../../../../../../../substrate/frame/message-queue" }
+
+# Polkadot
+xcm = { package = "staging-xcm", path = "../../../../../../../polkadot/xcm", default-features = false}
+pallet-xcm = { path = "../../../../../../../polkadot/xcm/pallet-xcm", default-features = false}
+xcm-executor = { package = "staging-xcm-executor",  path = "../../../../../../../polkadot/xcm/xcm-executor", default-features = false}
+
+# Bridges
+pallet-bridge-messages = { path = "../../../../../../../bridges/modules/messages", default-features = false}
+bp-messages = { path = "../../../../../../../bridges/primitives/messages", default-features = false}
+
+# Cumulus
+asset-test-utils = { path = "../../../../../../parachains/runtimes/assets/test-utils" }
+parachains-common = { path = "../../../../../../parachains/common" }
+cumulus-pallet-xcmp-queue = { path = "../../../../../../pallets/xcmp-queue", default-features = false}
+cumulus-pallet-dmp-queue = { path = "../../../../../../pallets/dmp-queue", default-features = false}
+bridge-hub-westend-runtime = { path = "../../../../../../parachains/runtimes/bridge-hubs/bridge-hub-westend", default-features = false }
+emulated-integration-tests-common = { path = "../../../common", default-features = false}
+westend-system-emulated-network ={ path = "../../../networks/westend-system" }