Add AspNetCoreSseServer sample (#81)

* Add AspNetCoreSseMcpTransport sample

* Fix build errors after rebase

* React to McpServerFactory changes

* Make Utf8JsonWriter non thread static

* Fix test errors caused by not rebasing the HttpLister changes on factory overhaul commit

tests/mcpdotnet.Tests/SseServerIntegrationTestFixture.cs

@@ -11,7 +11,6 @@ public class SseServerIntegrationTestFixture : IDisposable
     private Process _process;
 
     public ILoggerFactory LoggerFactory { get; }
-    public McpClientFactory Factory { get; }
     public McpClientOptions DefaultOptions { get; }
     public McpServerConfig DefaultConfig { get; }
 
@@ -24,7 +23,6 @@ public class SseServerIntegrationTestFixture : IDisposable
         DefaultOptions = new()
         {
             ClientInfo = new() { Name = "IntegrationTestClient", Version = "1.0.0" },
-            Capabilities = new() { Sampling = new(), Roots = new() }
         };
 
         DefaultConfig = new McpServerConfig
@@ -36,13 +34,6 @@ public class SseServerIntegrationTestFixture : IDisposable
             Location = "http://localhost:3001/sse"
         };
 
-        // Inject the mock transport into the factory
-        Factory = new McpClientFactory(
-            [DefaultConfig],
-            DefaultOptions,
-            LoggerFactory
-        );
-
         Start();
     }
 
@@ -70,7 +61,7 @@ public class SseServerIntegrationTestFixture : IDisposable
     {
         try
         {
-            var client = Factory.GetClientAsync("test_server").Result;
+            var client = McpClientFactory.CreateAsync(DefaultConfig, DefaultOptions, loggerFactory: LoggerFactory).GetAwaiter().GetResult();
             client.DisposeAsync().AsTask().Wait();
             LoggerFactory?.Dispose();
         }