Update runner to handle Dotcom/runner-admin based registration flow (#2487)

src/Sdk/DTWebApi/WebApi/ListRunnersResponse.cs

@@ -0,0 +1,50 @@
+using GitHub.Services.WebApi;
+using System;
+using System.Collections.Generic;
+using System.Runtime.Serialization;
+using Newtonsoft.Json;
+using System.Linq;
+
+namespace GitHub.DistributedTask.WebApi
+{
+
+    public class ListRunnersResponse
+    {
+        public ListRunnersResponse()
+        {
+        }
+
+        public ListRunnersResponse(ListRunnersResponse responseToBeCloned)
+        {
+            this.TotalCount = responseToBeCloned.TotalCount;
+            this.Runners = responseToBeCloned.Runners;
+        }
+
+        [JsonProperty("total_count")]
+        public int TotalCount
+        {
+            get;
+            set;
+        }
+
+        [JsonProperty("runners")]
+        public List<Runner> Runners
+        {
+            get;
+            set;
+        }
+
+        public ListRunnersResponse Clone()
+        {
+            return new ListRunnersResponse(this);
+        }
+
+        public List<TaskAgent> ToTaskAgents()
+        {
+            List<TaskAgent> taskAgents = new List<TaskAgent>();
+
+            return Runners.Select(runner => new TaskAgent() { Name = runner.Name }).ToList();
+        }
+    }
+
+}