Add StreamableHttpHandler and WithHttpTransport (#291)

* Simplify ModelContextProtocol.AspNetCore README

* Add StreamableHttpHandler

* Use "docker info" in CheckIsDockerAvailable

* Call WithHttpTransport in samples, tests and README

* Cleanup test namespaces

* Add CanConnect_WithMcpClient_AfterCustomizingRoute test

* Simplify relative URI handling

* Handle request made directly to the MapMcp route pattern

* Add Messages_FromNewUser_AreRejected test

* Fix README

* Shorten UserIdClaim ValueTuple names

* Remove MaxReconnectAttempts and ReconnectDelay from SseClientTransportOptions

- Add proper AdditionalHeaders support

samples/AspNetCoreSseServer/Program.cs

@@ -5,6 +5,7 @@ using OpenTelemetry;
 
 var builder = WebApplication.CreateBuilder(args);
 builder.Services.AddMcpServer()
+    .WithHttpTransport()
     .WithTools<EchoTool>()
     .WithTools<SampleLlmTool>();