Refactor message relay helpers (#1234)

* refactor message relay helpers

* single standalone_metrics function

* fixed tests

* clippy + fmt

* removed commented code

* add calls tracing

* fix spelling

* cargo fmt

* -commented code

* fix build again

* post-merge build fix

* clippy + fmt

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

@@ -181,7 +181,7 @@ impl<C: ChainWithBalances> Environment<C> for Client<C> {
 #[cfg(test)]
 mod tests {
 	use super::*;
-	use frame_support::weights::IdentityFee;
+	use frame_support::weights::{IdentityFee, Weight};
 	use futures::{
 		channel::mpsc::{unbounded, UnboundedReceiver, UnboundedSender},
 		future::FutureExt,
@@ -202,10 +202,18 @@ mod tests {
 		type Balance = u32;
 		type Index = u32;
 		type Signature = sp_runtime::testing::TestSignature;
+
+		fn max_extrinsic_size() -> u32 {
+			unreachable!()
+		}
+		fn max_extrinsic_weight() -> Weight {
+			unreachable!()
+		}
 	}
 
 	impl Chain for TestChain {
 		const NAME: &'static str = "Test";
+		const TOKEN_ID: Option<&'static str> = None;
 		const BEST_FINALIZED_HEADER_ID_METHOD: &'static str = "BestTestHeader";
 		const AVERAGE_BLOCK_INTERVAL: Duration = Duration::from_millis(1);
 		const STORAGE_PROOF_OVERHEAD: u32 = 0;