Integrate ChainApi with all messages (#1533)

* propagate chain_api subsystem through various locations

* add ChainApi to AllMessages

Co-authored-by: Peter Goodspeed-Niklaus <peter.r.goodspeedniklaus@gmail.com>

polkadot/node/subsystem/src/messages.rs

@@ -310,7 +310,7 @@ pub enum ChainApiMessage {
 		hash: Hash,
 		/// The number of ancestors to request.
 		k: usize,
-		/// The response channel. 
+		/// The response channel.
 		response_channel: ChainApiResponseChannel<Vec<Hash>>,
 	},
 }
@@ -488,6 +488,8 @@ pub enum AllMessages {
 	CandidateBacking(CandidateBackingMessage),
 	/// Message for the candidate selection subsystem.
 	CandidateSelection(CandidateSelectionMessage),
+	/// Message for the Chain API subsystem.
+	ChainApi(ChainApiMessage),
 	/// Message for the statement distribution subsystem.
 	StatementDistribution(StatementDistributionMessage),
 	/// Message for the availability distribution subsystem.