feat: add inital in memory dispatcher

Add a simple in memory dispatcher for scalar requests and stream request.

src/request.tests/_fixtures/ScalarChainedBehaviour1.cs

@@ -0,0 +1,13 @@
+// Copyright (c) The Geekeey Authors
+// SPDX-License-Identifier: EUPL-1.2
+
+namespace Geekeey.Request.Tests;
+
+public class ScalarChainedBehaviour1(ScalarTestTracker tracker) : IScalarRequestBehavior<ScalarTestRequest, string>
+{
+	public async Task<string> HandleAsync(ScalarTestRequest request, ScalarHandlerDelegate<string> next, CancellationToken cancellationToken)
+	{
+		tracker.Log.Add("Behaviour1");
+		return await next(request, cancellationToken);
+	}
+}