Initial Notification Updates and Support (#401)

* Bare bones of notifications working.

* Add MovieDownload event handler

To allow Download notificaitons

* Update pushover text to indicate movie

* Initial Notification Support

On Download and On Grab notifications should work.

* Telegram Notification Text

* Update Custom Script For Movies

* Update PP script WiKi page

Also added wiki page to Radarr wiki.

src/NzbDrone.Core/Notifications/NotificationBase.cs

@@ -24,6 +24,7 @@ namespace NzbDrone.Core.Notifications
         public abstract void OnGrab(GrabMessage grabMessage);
         public abstract void OnDownload(DownloadMessage message); 
         public abstract void OnRename(Series series);
+        public abstract void OnMovieRename(Movie movie);
 
         public virtual bool SupportsOnGrab => true;
         public virtual bool SupportsOnDownload => true;