Restructure Saxonite workspace and upgrade to .NET 10

Workspace/SaxoniteCoreWeb/Base/Middleware/SaxAuthenticationHandler.cs

@@ -0,0 +1,48 @@
+using Microsoft.AspNetCore.Authentication;
+using Microsoft.AspNetCore.Http;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+using System;
+using System.Collections.Generic;
+using System.Net;
+using System.Text;
+using System.Text.Encodings.Web;
+using System.Threading.Tasks;
+
+namespace Saxonite.Net.Core.Web.Base.Middleware
+{
+	//=======================================================================
+	// Authentication handler required to allow actions to issue Forbid() responses.
+	// Ref. https://stackoverflow.com/questions/54578426/why-do-i-need-to-set-a-defaultforbidscheme/54587054#54587054
+	//=======================================================================
+	public class SaxAuthenticationHandler : AuthenticationHandler<AuthenticationSchemeOptions>
+	{
+		//-------------------------------------------------------------------
+		// Data members.
+
+		//-------------------------------------------------------------------
+		public SaxAuthenticationHandler(IOptionsMonitor<AuthenticationSchemeOptions> options, ILoggerFactory logger, UrlEncoder encoder, ISystemClock clock) :
+		base(options, logger, encoder, clock)
+		{
+		}
+
+		//-------------------------------------------------------------------
+		protected override Task HandleForbiddenAsync(AuthenticationProperties properties)
+		{
+			Context.Response.StatusCode = (int)HttpStatusCode.Forbidden;
+			return base.HandleForbiddenAsync(properties);
+		}
+
+		//-------------------------------------------------------------------
+		protected override async Task<AuthenticateResult> HandleAuthenticateAsync()
+		{
+			// NoOp task to avoid compiler warning.
+			await Task.CompletedTask;
+			Context.Response.StatusCode = (int)HttpStatusCode.Unauthorized;
+			return AuthenticateResult.NoResult();
+		}
+
+		//-------------------------------------------------------------------
+	}
+	//=======================================================================
+}