Allow Flow.getNode to return subflowInstance nodes

Related to #2898

packages/node_modules/@node-red/runtime/lib/flows/Flow.js

@@ -318,7 +318,7 @@ class Flow {
             }
         });
         stopList = nodesToStop.concat(configsToStop);
-        
+
         var promises = [];
         for (i=0;i<stopList.length;i++) {
             var node = this.activeNodes[stopList[i]];
@@ -376,6 +376,8 @@ class Flow {
         } else if (this.activeNodes[id]) {
             // TEMP: this is a subflow internal node within this flow
             return this.activeNodes[id];
+        } else if (this.subflowInstanceNodes[id]) {
+            return this.subflowInstanceNodes[id];
         } else if (cancelBubble) {
             // The node could be inside one of this flow's subflows
             var node;