Bridges subtree update (#2602)

## Summary

This PR aligns Rococo/Westend bridge with latest Bridges repo
development:
- https://github.com/paritytech/parity-bridges-common/pull/2727
- https://github.com/paritytech/parity-bridges-common/pull/2728
- https://github.com/paritytech/parity-bridges-common/pull/2729




Part of: https://github.com/paritytech/parity-bridges-common/issues/2452

bridges/primitives/xcm-bridge-hub/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "bp-xcm-bridge-hub"
+description = "Primitives of the xcm-bridge-hub pallet."
+version = "0.1.0"
+authors.workspace = true
+edition.workspace = true
+license = "GPL-3.0-or-later WITH Classpath-exception-2.0"
+
+[dependencies]
+
+# Substrate Dependencies
+sp-std = { path = "../../../substrate/primitives/std", default-features = false }
+
+[features]
+default = ["std"]
+std = ["sp-std/std"]

bridges/primitives/xcm-bridge-hub/src/lib.rs

@@ -0,0 +1,24 @@
+// Copyright 2019-2021 Parity Technologies (UK) Ltd.
+// This file is part of Parity Bridges Common.
+
+// Parity Bridges Common is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity Bridges Common is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity Bridges Common.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Primitives of the xcm-bridge-hub pallet.
+
+#![warn(missing_docs)]
+#![cfg_attr(not(feature = "std"), no_std)]
+
+/// Encoded XCM blob. We expect the bridge messages pallet to use this blob type for both inbound
+/// and outbound payloads.
+pub type XcmAsPlainPayload = sp_std::vec::Vec<u8>;