Add incoming attr for application node.

apm-protocol/apm-ui-protocol/src/main/resources/ui-graphql/application-layer.graphqls

@@ -19,6 +19,9 @@ type ApplicationNode implements Node {
     numOfServerAlarm: Int!
     # The number of services alerting
     numOfServiceAlarm: Int!
+    # Incoming request node, means User or outside system access the cluster from this.
+    # Recommend the UI generate a User node for each incoming node
+    isIncomingNode: Boolean
 }
 
 # The conjectural node generated by exit span