Improve code structure

- Add separate API project
- Add notification system

HyperbolicDownloaderApi/Networking/BroadcastRecivedEventArgs.cs

@@ -0,0 +1,15 @@
+using System.Net;
+
+namespace HyperbolicDownloaderApi.Networking;
+
+internal class BroadcastRecivedEventArgs : EventArgs
+{
+    public BroadcastRecivedEventArgs(IPEndPoint iPEndPoint, string message)
+    {
+        IPEndPoint = iPEndPoint;
+        Message = message;
+    }
+
+    public IPEndPoint IPEndPoint { get; }
+    public string Message { get; }
+}