Started implementing oauth2 based on MoonCore helper services

Its more or less a test how well the helper services improve the implementation. I havent implemented anything fancy here atm. Just testing the oauth2 flow

Moonlight.Shared/Http/Responses/Auth/AuthStartResponse.cs

@@ -0,0 +1,8 @@
+namespace Moonlight.Shared.Http.Responses.Auth;
+
+public class AuthStartResponse
+{
+    public string Endpoint { get; set; }
+    public string ClientId { get; set; }
+    public string RedirectUri { get; set; }
+}