Tests for BridgeHub(s) <> remote GRANDPA chain (#2692)

So far the `bridge-hub-test-utils` contained a tests set for testing
BridgeHub runtime that is bridging with the remote **parachain**. But we
have https://github.com/paritytech/polkadot-sdk/pull/2540 coming, which
would add Rococo <> Bulletin chain bridge (where Bulletin = standalone
chain that is using GRANDPA finality). Then it'll be expanded to
Polkadot BH as well.

So this PR adds the same set of tests to the `bridge-hub-test-utils`,
but for the case when remote chain is the chain with GRANDPA finality.
There's a lot of changes in this PR - I'll describe some:
- I've added `BasicParachainRuntime` trait to decrease number of lines
we need to add to `where` clause. Could revert, but imo it is useful;
- `cumulus/parachains/runtimes/bridge-hubs/test-utils/src/test_data` is
a submodule for generating test data for the test sets.
`from_parachain.rs` is used in tests for the case when remote chain is a
parachain, `from_grandpa_chain.rs` - for the bridges with remote GRANDPA
chains. `mod.rs` has some code, shared by both types of tests;
- `cumulus/parachains/runtimes/bridge-hubs/test-utils/src/test_data` is
a submodule with all test cases. The `mod.rs` has tests, suitable for
all cases. There's also `wth_parachain.rs` and `with_grandpa_chain.rs`
with the same meaning as above;
- I've merged the "core" code of two previous tests -
`relayed_incoming_message_works` and `complex_relay_extrinsic_works`
into one single `relayed_incoming_message_works` test. So now we are
always constructing extrinsics and are dispatching them using executive
module (meaning all signed extensions are also tested).

New test set is used here:
https://github.com/paritytech/polkadot-sdk/pull/2540. Once this PR is
merged, I'll merge that other PR with master to remove duplicate
changes.

I'm also planning to cleanup generic constraints + remove some
unnecessary assumptions about used chains in a follow-up PRs. But for
now I think this PR has enough changes, so don't want to complicate it
even more.

---

Breaking changes for the code that have used those tests before:
- the `construct_and_apply_extrinsic` callback now accepts the
`RuntimeCall` instead of the `pallet_utility::Call`;
- the `construct_and_apply_extrinsic` now may be called multiple times
for the single test, so make sure the `frame_system::CheckNonce` is
correctly constructed;
- all previous tests have been moved from
`bridge_hub_test_utils::test_cases` to
`bridge_hub_test_utils::test_cases::from_parachain` module;
- there are several changes in test arguments - please refer to
https://github.com/paritytech/polkadot-sdk/compare/sv-tests-for-bridge-with-remote-grandpa-chain?expand=1#diff-79a28d4d3e1749050341c2424f00c4c139825b1a20937767f83e58b95166735c
for details.

cumulus/parachains/runtimes/bridge-hubs/test-utils/src/test_data/mod.rs

@@ -0,0 +1,144 @@
+// Copyright (C) Parity Technologies (UK) Ltd.
+// This file is part of Cumulus.
+
+// Cumulus 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.
+
+// Cumulus 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 Cumulus.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Generating test data, used by all tests.
+
+pub mod from_grandpa_chain;
+pub mod from_parachain;
+
+use bp_messages::{
+	target_chain::{DispatchMessage, DispatchMessageData},
+	LaneId, MessageKey,
+};
+use codec::Encode;
+use frame_support::traits::Get;
+use pallet_bridge_grandpa::BridgedHeader;
+use xcm::latest::prelude::*;
+
+use bp_messages::MessageNonce;
+use bp_runtime::BasicOperatingMode;
+use bp_test_utils::authority_list;
+use xcm::GetVersion;
+use xcm_builder::{HaulBlob, HaulBlobError, HaulBlobExporter};
+use xcm_executor::traits::{validate_export, ExportXcm};
+
+pub fn prepare_inbound_xcm<InnerXcmRuntimeCall>(
+	xcm_message: Xcm<InnerXcmRuntimeCall>,
+	destination: InteriorMultiLocation,
+) -> Vec<u8> {
+	let location = xcm::VersionedInteriorMultiLocation::V3(destination);
+	let xcm = xcm::VersionedXcm::<InnerXcmRuntimeCall>::V3(xcm_message);
+	// this is the `BridgeMessage` from polkadot xcm builder, but it has no constructor
+	// or public fields, so just tuple
+	// (double encoding, because `.encode()` is called on original Xcm BLOB when it is pushed
+	// to the storage)
+	(location, xcm).encode().encode()
+}
+
+/// Helper that creates InitializationData mock data, that can be used to initialize bridge
+/// GRANDPA pallet
+pub fn initialization_data<
+	Runtime: pallet_bridge_grandpa::Config<GrandpaPalletInstance>,
+	GrandpaPalletInstance: 'static,
+>(
+	block_number: u32,
+) -> bp_header_chain::InitializationData<BridgedHeader<Runtime, GrandpaPalletInstance>> {
+	bp_header_chain::InitializationData {
+		header: Box::new(bp_test_utils::test_header(block_number.into())),
+		authority_list: authority_list(),
+		set_id: 1,
+		operating_mode: BasicOperatingMode::Normal,
+	}
+}
+
+/// Dummy xcm
+pub(crate) fn dummy_xcm() -> Xcm<()> {
+	vec![Trap(42)].into()
+}
+
+pub(crate) fn dispatch_message(
+	lane_id: LaneId,
+	nonce: MessageNonce,
+	payload: Vec<u8>,
+) -> DispatchMessage<Vec<u8>> {
+	DispatchMessage {
+		key: MessageKey { lane_id, nonce },
+		data: DispatchMessageData { payload: Ok(payload) },
+	}
+}
+
+/// Macro used for simulate_export_message and capturing bytes
+macro_rules! grab_haul_blob (
+	($name:ident, $grabbed_payload:ident) => {
+		std::thread_local! {
+			static $grabbed_payload: std::cell::RefCell<Option<Vec<u8>>> = std::cell::RefCell::new(None);
+		}
+
+		struct $name;
+		impl HaulBlob for $name {
+			fn haul_blob(blob: Vec<u8>) -> Result<(), HaulBlobError>{
+				$grabbed_payload.with(|rm| *rm.borrow_mut() = Some(blob));
+				Ok(())
+			}
+		}
+	}
+);
+
+/// Simulates `HaulBlobExporter` and all its wrapping and captures generated plain bytes,
+/// which are transferred over bridge.
+pub(crate) fn simulate_message_exporter_on_bridged_chain<
+	SourceNetwork: Get<NetworkId>,
+	DestinationNetwork: Get<MultiLocation>,
+	DestinationVersion: GetVersion,
+>(
+	(destination_network, destination_junctions): (NetworkId, Junctions),
+) -> Vec<u8> {
+	grab_haul_blob!(GrabbingHaulBlob, GRABBED_HAUL_BLOB_PAYLOAD);
+
+	// lets pretend that some parachain on bridged chain exported the message
+	let universal_source_on_bridged_chain =
+		X2(GlobalConsensus(SourceNetwork::get()), Parachain(5678));
+	let channel = 1_u32;
+
+	// simulate XCM message export
+	let (ticket, fee) = validate_export::<
+		HaulBlobExporter<GrabbingHaulBlob, DestinationNetwork, DestinationVersion, ()>,
+	>(
+		destination_network,
+		channel,
+		universal_source_on_bridged_chain,
+		destination_junctions,
+		dummy_xcm(),
+	)
+	.expect("validate_export to pass");
+	log::info!(
+		target: "simulate_message_exporter_on_bridged_chain",
+		"HaulBlobExporter::validate fee: {:?}",
+		fee
+	);
+	let xcm_hash =
+		HaulBlobExporter::<GrabbingHaulBlob, DestinationNetwork, DestinationVersion, ()>::deliver(
+			ticket,
+		)
+		.expect("deliver to pass");
+	log::info!(
+		target: "simulate_message_exporter_on_bridged_chain",
+		"HaulBlobExporter::deliver xcm_hash: {:?}",
+		xcm_hash
+	);
+
+	GRABBED_HAUL_BLOB_PAYLOAD.with(|r| r.take().expect("Encoded message should be here"))
+}