Complete refactor, reasync, rebuild listener

ntfysh_client/SubscribedTopic.cs

@@ -1,25 +1,30 @@
-using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
 using Newtonsoft.Json;
 
 namespace ntfysh_client
 {
     public class SubscribedTopic
     {
-        public SubscribedTopic(string topicId, string serverUrl, string username, string password, StreamReader stream)
+        public SubscribedTopic(string topicId, string serverUrl, string? username, string? password, Task runner, CancellationTokenSource runnerCanceller)
         {
             TopicId = topicId;
             ServerUrl = serverUrl;
             Username = username;
             Password = password;
-            Stream = stream;
+            Runner = runner;
+            RunnerCanceller = runnerCanceller;
         }
 
         public string TopicId { get; }
         public string ServerUrl { get; }
-        public string Username { get; }
-        public string Password { get; }
+        public string? Username { get; }
+        public string? Password { get; }
 
         [JsonIgnore]
-        public StreamReader Stream { get; }
+        public Task Runner { get; }
+        
+        [JsonIgnore]
+        public CancellationTokenSource RunnerCanceller { get; }
     }
 }