New: Add support for Simplepush notifications (#6597)

* New: Add support for Simplepush notifications

* Add HelpText for Simplepush Events field

src/NzbDrone.Core/Notifications/Simplepush/Simplepush.cs

@@ -0,0 +1,53 @@
+using System.Collections.Generic;
+using FluentValidation.Results;
+using NzbDrone.Common.Extensions;
+
+namespace NzbDrone.Core.Notifications.Simplepush
+{
+    public class Simplepush : NotificationBase<SimplepushSettings>
+    {
+        private readonly ISimplepushProxy _proxy;
+
+        public Simplepush(ISimplepushProxy proxy)
+        {
+            _proxy = proxy;
+        }
+
+        public override string Name => "Simplepush";
+        public override string Link => "https://simplepush.io/";
+
+        public override void OnGrab(GrabMessage grabMessage)
+        {
+            _proxy.SendNotification(MOVIE_GRABBED_TITLE, grabMessage.Message, Settings);
+        }
+
+        public override void OnDownload(DownloadMessage message)
+        {
+            _proxy.SendNotification(MOVIE_DOWNLOADED_TITLE, message.Message, Settings);
+        }
+
+        public override void OnMovieFileDelete(MovieFileDeleteMessage deleteMessage)
+        {
+            _proxy.SendNotification(MOVIE_FILE_DELETED_TITLE, deleteMessage.Message, Settings);
+        }
+
+        public override void OnMovieDelete(MovieDeleteMessage deleteMessage)
+        {
+            _proxy.SendNotification(MOVIE_DELETED_TITLE, deleteMessage.Message, Settings);
+        }
+
+        public override void OnHealthIssue(HealthCheck.HealthCheck healthCheck)
+        {
+            _proxy.SendNotification(HEALTH_ISSUE_TITLE, healthCheck.Message, Settings);
+        }
+
+        public override ValidationResult Test()
+        {
+            var failures = new List<ValidationFailure>();
+
+            failures.AddIfNotNull(_proxy.Test(Settings));
+
+            return new ValidationResult(failures);
+        }
+    }
+}