Bridges - changes for Bridges V2 - relay client part (#4494)

Contains mainly changes/nits/refactors related to the relayer code
(`client-substrate` and `lib-substrate-relay`) migrated from the Bridges
V2 [branch](#4427).

Relates to:
paritytech/parity-bridges-common#2976
Companion: paritytech/parity-bridges-common#2988


## TODO
- [x] fix comments

## Questions
- [x] Do we need more testing for client V2 stuff? If so, how/what is
the ultimate test? @svyatonik
- [x] check
[comment](#4494 (comment))
for more testing

---------

Co-authored-by: Svyatoslav Nikolsky <svyatonik@gmail.com>
Co-authored-by: Serban Iorga <serban@parity.io>

bridges/modules/relayers/src/lib.rs

@@ -63,7 +63,7 @@ pub mod pallet {
 		/// The overarching event type.
 		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
 		/// Type of relayer reward.
-		type Reward: AtLeast32BitUnsigned + Copy + Parameter + MaxEncodedLen;
+		type Reward: AtLeast32BitUnsigned + Copy + Member + Parameter + MaxEncodedLen;
 		/// Pay rewards scheme.
 		type PaymentProcedure: PaymentProcedure<Self::AccountId, Self::Reward>;
 		/// Stake and slash scheme.

bridges/primitives/relayers/src/lib.rs

@@ -140,8 +140,8 @@ pub struct RelayerRewardsKeyProvider<AccountId, Reward>(PhantomData<(AccountId,
 
 impl<AccountId, Reward> StorageDoubleMapKeyProvider for RelayerRewardsKeyProvider<AccountId, Reward>
 where
-	AccountId: Codec + EncodeLike,
-	Reward: Codec + EncodeLike,
+	AccountId: 'static + Codec + EncodeLike + Send + Sync,
+	Reward: 'static + Codec + EncodeLike + Send + Sync,
 {
 	const MAP_NAME: &'static str = "RelayerRewards";
 

bridges/primitives/runtime/src/lib.rs

@@ -255,9 +255,9 @@ pub trait StorageMapKeyProvider {
 	/// The same as `StorageMap::Hasher1`.
 	type Hasher: StorageHasher;
 	/// The same as `StorageMap::Key1`.
-	type Key: FullCodec;
+	type Key: FullCodec + Send + Sync;
 	/// The same as `StorageMap::Value`.
-	type Value: FullCodec;
+	type Value: 'static + FullCodec;
 
 	/// This is a copy of the
 	/// `frame_support::storage::generator::StorageMap::storage_map_final_key`.
@@ -277,13 +277,13 @@ pub trait StorageDoubleMapKeyProvider {
 	/// The same as `StorageDoubleMap::Hasher1`.
 	type Hasher1: StorageHasher;
 	/// The same as `StorageDoubleMap::Key1`.
-	type Key1: FullCodec;
+	type Key1: FullCodec + Send + Sync;
 	/// The same as `StorageDoubleMap::Hasher2`.
 	type Hasher2: StorageHasher;
 	/// The same as `StorageDoubleMap::Key2`.
-	type Key2: FullCodec;
+	type Key2: FullCodec + Send + Sync;
 	/// The same as `StorageDoubleMap::Value`.
-	type Value: FullCodec;
+	type Value: 'static + FullCodec;
 
 	/// This is a copy of the
 	/// `frame_support::storage::generator::StorageDoubleMap::storage_double_map_final_key`.

bridges/relays/client-substrate/Cargo.toml

@@ -22,6 +22,7 @@ rand = "0.8.5"
 scale-info = { version = "2.11.1", features = ["derive"] }
 tokio = { version = "1.37", features = ["rt-multi-thread"] }
 thiserror = { workspace = true }
+quick_cache = "0.3"
 
 # Bridge dependencies
 

bridges/relays/client-substrate/src/chain.rs

@@ -36,6 +36,9 @@ use sp_runtime::{
 };
 use std::{fmt::Debug, time::Duration};
 
+/// Signed block type of given chain.
+pub type SignedBlockOf<C> = <C as Chain>::SignedBlock;
+
 /// Substrate-based chain from minimal relay-client point of view.
 pub trait Chain: ChainBase + Clone {
 	/// Chain name.