chore: update gas estimate query response (#1248)

# Background

Small change needed on the contract between Paloma/Pigeon.

# Testing completed

- [x] test coverage exists or has been added/updated
- [ ] tested in a private testnet

# Breaking changes

- [x] I have checked my code for breaking changes
- [x] If there are breaking changes, there is a supporting migration.

proto/palomachain/paloma/consensus/query.proto

@@ -160,5 +160,5 @@ message QueryQueuedMessagesForGasEstimationRequest {
 }
 
 message QueryQueuedMessagesForGasEstimationResponse {
-  repeated MessageToSign messagesToEstimate = 1 [ (gogoproto.nullable) = false ];
+  repeated MessageWithSignatures messagesToEstimate = 1 [ (gogoproto.nullable) = false ];
 }

x/consensus/keeper/query_queued_messages_for_gas_estimation.go

@@ -21,9 +21,15 @@ func (k Keeper) QueuedMessagesForGasEstimation(goCtx context.Context, req *types
 		return nil, fmt.Errorf("failed to query messages for gas estimation: %w", err)
 	}
 
-	var res []types.MessageToSign
+	var res []types.MessageWithSignatures
 	for _, msg := range msgs {
-		res = append(res, *queuedMessageToMessageToSign(k.cdc, msg))
+		if msg.GetRequireSignatures() {
+			msgWithSignatures, err := k.queuedMessageToMessageWithSignatures(msg)
+			if err != nil {
+				return nil, fmt.Errorf("failed to convert queued message to message with signatures: %w", err)
+			}
+			res = append(res, msgWithSignatures)
+		}
 	}
 
 	return &types.QueryQueuedMessagesForGasEstimationResponse{