Check that the validation code matches the parachain code (#3433)

This introduces a check to ensure that the parachain code matches the
validation code stored in the relay chain state. If not, it will print a
warning. This should be mainly useful for parachain builders to make
sure they have setup everything correctly.

cumulus/client/relay-chain-inprocess-interface/src/lib.rs

@@ -21,7 +21,7 @@ use cumulus_primitives_core::{
 	relay_chain::{
 		runtime_api::ParachainHost, Block as PBlock, BlockId, CommittedCandidateReceipt,
 		Hash as PHash, Header as PHeader, InboundHrmpMessage, OccupiedCoreAssumption, SessionIndex,
-		ValidatorId,
+		ValidationCodeHash, ValidatorId,
 	},
 	InboundDownwardMessage, ParaId, PersistedValidationData,
 };
@@ -115,6 +115,19 @@ impl RelayChainInterface for RelayChainInProcessInterface {
 		)?)
 	}
 
+	async fn validation_code_hash(
+		&self,
+		hash: PHash,
+		para_id: ParaId,
+		occupied_core_assumption: OccupiedCoreAssumption,
+	) -> RelayChainResult<Option<ValidationCodeHash>> {
+		Ok(self.full_client.runtime_api().validation_code_hash(
+			hash,
+			para_id,
+			occupied_core_assumption,
+		)?)
+	}
+
 	async fn candidate_pending_availability(
 		&self,
 		hash: PHash,