New relayer rewards scheme integration (#1652)

* relayer rewards integration: initial commit

* added refund-relayer-extension to the millau runtime

* spelling

* spelling again

* new -> Default

bridges/primitives/messages/src/lib.rs

@@ -24,6 +24,7 @@ use bp_runtime::{BasicOperatingMode, OperatingMode};
 use codec::{Decode, Encode, MaxEncodedLen};
 use frame_support::RuntimeDebug;
 use scale_info::TypeInfo;
+use source_chain::RelayersRewards;
 use sp_core::TypeId;
 use sp_std::{collections::vec_deque::VecDeque, ops::RangeInclusive, prelude::*};
 
@@ -364,19 +365,16 @@ pub fn total_unrewarded_messages<RelayerId>(
 pub fn calc_relayers_rewards<AccountId>(
 	messages_relayers: VecDeque<UnrewardedRelayer<AccountId>>,
 	received_range: &RangeInclusive<MessageNonce>,
-) -> source_chain::RelayersRewards<AccountId>
+) -> RelayersRewards<AccountId>
 where
 	AccountId: sp_std::cmp::Ord,
 {
 	// remember to reward relayers that have delivered messages
 	// this loop is bounded by `T::MaxUnrewardedRelayerEntriesAtInboundLane` on the bridged chain
-	let mut relayers_rewards = source_chain::RelayersRewards::new();
+	let mut relayers_rewards = RelayersRewards::new();
 	for entry in messages_relayers {
 		let nonce_begin = sp_std::cmp::max(entry.messages.begin, *received_range.start());
 		let nonce_end = sp_std::cmp::min(entry.messages.end, *received_range.end());
-
-		// loop won't proceed if current entry is ahead of received range (begin > end).
-		// this loop is bound by `T::MaxUnconfirmedMessagesAtInboundLane` on the bridged chain
 		if nonce_end >= nonce_begin {
 			*relayers_rewards.entry(entry.relayer).or_default() += nonce_end - nonce_begin + 1;
 		}