[Bug] GraphQL queries assume nodes' names equal their connection URLs

[andrewazores]

          Found it. Looks like the error is because we have been assuming that nodes' names is equal to their connection URLs. That's true for some discovery mechanisms, but is not a hard requirement and is not true for Agent self-published targets.

        {
            "children": [
                {
                    "children": [],
                    "id": 15,
                    "labels": [],
                    "name": "quarkus-test-agent-agent-05ca9557-7b36-4a43-a3d0-360b45ffc9c9",
                    "nodeType": "JVM",
                    "target": {
                        "agent": true,
                        "alias": "quarkus-test-agent",
                        "annotations": {
                            "cryostat": [
                                {
                                    "key": "PID",
                                    "value": "1"
                                },
                                {
                                    "key": "HOST",
                                    "value": "quarkus-test-agent"
                                },
                                {
                                    "key": "PORT",
                                    "value": "9977"
                                },
                                {
                                    "key": "REALM",
                                    "value": "quarkus-test-agent"
                                },
                                {
                                    "key": "JAVA_MAIN",
                                    "value": "/deployments/quarkus-run.jar"
                                },
                                {
                                    "key": "START_TIME",
                                    "value": "1713534670"
                                }
                            ],
                            "platform": [
                                {
                                    "key": "INSTANCE_ID",
                                    "value": "5306e66d-de36-460b-ab40-e96fa40c2ea2"
                                }
                            ]
                        },
                        "connectUrl": "http://quarkus-test-agent:9977/",
                        "id": 9,
                        "jvmId": "GjQ8uAWjIn768jrHC8SUzDVVOs64Anel5nOa4vt4K-I=",
                        "labels": []
                    }
                }
            ],
            "id": 14,
            "labels": [],
            "name": "quarkus-test-agent",
            "nodeType": "Realm"
        }

vs

                {
                    "children": [],
                    "id": 9,
                    "labels": [],
                    "name": "service:jmx:rmi:///jndi/rmi://vertx-fib-demo-2:9094/jmxrmi",
                    "nodeType": "JVM",
                    "target": {
                        "agent": false,
                        "alias": "es.andrewazor.demo.Main",
                        "annotations": {
                            "cryostat": [
                                {
                                    "key": "HOST",
                                    "value": "vertx-fib-demo-2"
                                },
                                {
                                    "key": "PORT",
                                    "value": "9094"
                                },
                                {
                                    "key": "REALM",
                                    "value": "JDP"
                                },
                                {
                                    "key": "JAVA_MAIN",
                                    "value": "es.andrewazor.demo.Main"
                                }
                            ],
                            "platform": []
                        },
                        "connectUrl": "service:jmx:rmi:///jndi/rmi://vertx-fib-demo-2:9094/jmxrmi",
                        "id": 5,
                        "jvmId": null,
                        "labels": []
                    }
                }

Originally posted by @andrewazores in https://github.com/cryostatio/cryostat3/issues/342#issuecomment-2066640908