ONOS-4326: TopoRegions: MockServer scenario with skeleton events.

The plan is to augment these events as we figure out what they will look like when populated.

Change-Id: I3aa1cb22a6e339bf9f6f86fc1587783c0f63a9b6

+{
+  "event": "topo2AllInstances",
+  "payload": {
+    "members": [{
+      "id": "127.0.0.1",
+      "ip": "127.0.0.1",
+      "online": true,
+      "ready": true,
+      "uiAttached": true,
+      "switches": 12
+    }]
+  }
+}
\ No newline at end of file

+{
+  "event": "topo2CurrentLayout",
+  "payload": {
+    "id": "_default_",
+    "parent": "",
+    "region": "",
+    "regionName": ""
+  }
+}

+{
+  "event": "topo2CurrentRegion",
+  "payload": {
+    "note": "no-region"
+  }
+}

+{
+  "event": "topo2PeerRegions",
+  "payload": {
+    "peers": []
+  }
+}

+{
+  "event": "topo2Orphans",
+  "payload": {
+    "devices": [
+      []
+    ],
+    "hosts": [
+      []
+    ],
+    "links": [],
+    "layerOrder": ["def"]
+  }
+}

+{
+  "event": "topo2StartDone",
+  "payload": {}
+}

+{
+  "comments": [
+    "Topo 2 - initial scenario for start up events",
+    "This sequence would occur after receiving 'topo2start'..."
+  ],
+  "title": "Topo 2 A",
+  "params": {
+    "lastAuto": 0
+  },
+  "description": [
+    "Press 'a' to load initial events.",
+    "Press 'n' to fire further events."
+  ]
+}