multi: query probabilities for blinded paths from new MC namespace

Start querying blinded path probabilites from the new MC namespace where
the results of successful blinded path receives will be written to.

routing/missioncontrol.go

@@ -76,6 +76,11 @@ const (
 	// control name space. This is used as the sub-bucket key within the
 	// top level DB bucket to store mission control results.
 	DefaultMissionControlNamespace = "default"
+
+	// BlindedPathMissionControlNamespace is the name of the mission control
+	// namespace where results from successful blinded path receives will
+	// be stored.
+	BlindedPathMissionControlNamespace = "blinded-paths"
 )
 
 var (

rpcserver.go

@@ -5829,6 +5829,14 @@ func (r *rpcServer) AddInvoice(ctx context.Context,
 			"be included in each path")
 	}
 
+	blindedPathMC, err := r.server.missionController.GetNamespacedStore(
+		routing.BlindedPathMissionControlNamespace,
+	)
+	if err != nil {
+		return nil, fmt.Errorf("could not initialise mission control "+
+			"in the blinded paths namespace: %w", err)
+	}
+
 	addInvoiceCfg := &invoicesrpc.AddInvoiceConfig{
 		AddInvoice:        r.server.invoices.AddInvoice,
 		IsChannelActive:   r.server.htlcSwitch.HasActiveLink,
@@ -5867,8 +5875,7 @@ func (r *rpcServer) AddInvoice(ctx context.Context,
 			[]*route.Route, error) {
 
 			return r.server.chanRouter.FindBlindedPaths(
-				r.selfNode, amt,
-				r.server.defaultMC.GetProbability,
+				r.selfNode, amt, blindedPathMC.GetProbability,
 				blindingRestrictions,
 			)
 		},

server.go

@@ -932,7 +932,7 @@ func newServer(cfg *Config, listenAddrs []net.Addr,
 	}
 
 	blindedPathMC, err := s.missionController.GetNamespacedStore(
-		"blinded-path",
+		routing.BlindedPathMissionControlNamespace,
 	)
 	if err != nil {
 		return nil, fmt.Errorf("can't create mission control in the "+