Add RialtoParachain <> Millau bridge to test deployments (#1412)

* add RialtoParachain <> Millau bridge to test deployments

* flush (still not working, but possible fix in comments)

* proper fix

* fixed on-demand parachains relay case: if better relay header is delivered, then we must select para header that may be proved using this relay header

* dashboards

* fmt

* removing debugging code

* more cleanup

bridges/relays/parachains/src/parachains_loop.rs

@@ -121,7 +121,7 @@ pub trait TargetClient<P: ParachainsPipeline>: RelayClient {
 /// Return prefix that will be used by default to expose Prometheus metrics of the parachains
 /// sync loop.
 pub fn metrics_prefix<P: ParachainsPipeline>() -> String {
-	format!("{}_to_{}_Sync", P::SourceChain::NAME, P::TargetChain::NAME)
+	format!("{}_to_{}_Parachains", P::SourceChain::NAME, P::TargetChain::NAME)
 }
 
 /// Run parachain heads synchronization.