Rococo <> Wococo relayer balance guard (#998)

* relayer balance guards in Rococo <> Wococo

* removed printlns

* update constant

* update constant

* start balance guard for Wococo -> Rococo

* Update relays/bin-substrate/src/chains/wococo_headers_to_rococo.rs

Co-authored-by: Hernando Castano <HCastano@users.noreply.github.com>

* Update relays/bin-substrate/src/chains/wococo_headers_to_rococo.rs

Co-authored-by: Hernando Castano <HCastano@users.noreply.github.com>
Co-authored-by: Tomasz Drwięga <tomusdrw@users.noreply.github.com>
Co-authored-by: Tomasz Drwięga <tomasz@parity.io>

bridges/primitives/chain-rococo/src/lib.rs

@@ -22,6 +22,7 @@
 
 use bp_messages::{LaneId, MessageDetails, MessageNonce, UnrewardedRelayersState};
 use bp_runtime::Chain;
+use frame_support::weights::{WeightToFeeCoefficient, WeightToFeeCoefficients, WeightToFeePolynomial};
 use sp_std::prelude::*;
 use sp_version::RuntimeVersion;
 
@@ -43,6 +44,23 @@ pub const VERSION: RuntimeVersion = RuntimeVersion {
 	transaction_version: 0,
 };
 
+// NOTE: This needs to be kept up to date with the Rococo runtime found in the Polkadot repo.
+pub struct WeightToFee;
+impl WeightToFeePolynomial for WeightToFee {
+	type Balance = Balance;
+	fn polynomial() -> WeightToFeeCoefficients<Balance> {
+		const CENTS: Balance = 1_000_000_000_000 / 100;
+		let p = CENTS;
+		let q = 10 * Balance::from(ExtrinsicBaseWeight::get());
+		smallvec::smallvec![WeightToFeeCoefficient {
+			degree: 1,
+			negative: false,
+			coeff_frac: Perbill::from_rational(p % q, q),
+			coeff_integer: p / q,
+		}]
+	}
+}
+
 /// Rococo Runtime `Call` enum.
 ///
 /// The enum represents a subset of possible `Call`s we can send to Rococo chain.