Renamed DownloadNewChaptersTask to MonitorPublicationTask

Added TrangaTask.Clone() method
Rewrote TrangaTask.progress for the billionth+1 time.
Removed Increment and DecrementProgress methods
Removed TrangaTask.ReplaceFailedChildTask method
Changed return type of TrangaTask.ExecuteTask to bool, signifying success.
Added Failed Execution state to TrangaTask
Replaced taskManager failed-task logic
Removed TaskManager bulky AddTask and DeleteTask methods
Removed TaskManager bulky Constructor

Tranga/TrangaTasks/MonitorPublicationTask.cs

@@ -0,0 +1,59 @@
+using Logging;
+
+namespace Tranga.TrangaTasks;
+
+public class MonitorPublicationTask : TrangaTask
+{
+    public string connectorName { get; }
+    public Publication publication { get; }
+    public string language { get; }
+    public MonitorPublicationTask(string connectorName, Publication publication, TimeSpan reoccurrence, string language = "en") : base(Task.MonitorPublication, reoccurrence)
+    {
+        this.connectorName = connectorName;
+        this.publication = publication;
+        this.language = language;
+    }
+
+    protected override bool ExecuteTask(TaskManager taskManager, Logger? logger, CancellationToken? cancellationToken = null)
+    {
+        if (cancellationToken?.IsCancellationRequested??false)
+            return false;
+        Connector connector = taskManager.GetConnector(this.connectorName);
+        
+        //Check if Publication already has a Folder
+        publication.CreatePublicationFolder(taskManager.settings.downloadLocation);
+        List<Chapter> newChapters = taskManager.GetNewChaptersList(connector, publication, language);
+
+        connector.CopyCoverFromCacheToDownloadLocation(publication, taskManager.settings);
+        
+        publication.SaveSeriesInfoJson(connector.downloadLocation);
+
+        foreach (Chapter newChapter in newChapters)
+        {
+            DownloadChapterTask newTask = new (this.connectorName, publication, newChapter, this.language, this);
+            this.childTasks.Add(newTask);
+            newTask.state = ExecutionState.Enqueued;
+            taskManager.AddTask(newTask);
+        }
+
+        return true;
+    }
+
+    public override TrangaTask Clone()
+    {
+        return new MonitorPublicationTask(this.connectorName, this.publication, this.reoccurrence,
+            this.language);
+    }
+
+    protected override double GetProgress()
+    {
+        if (this.childTasks.Count > 0)
+            return this.childTasks.Sum(ct => ct.progress) / childTasks.Count;
+        return 1;
+    }
+
+    public override string ToString()
+    {
+        return $"{base.ToString()}, {connectorName}, {publication.sortName} {publication.internalId}";
+    }
+}