feat(transport): support streamable http server (#152)

* feat(transport): support streamable http server

* refactor(transport): add common module for shared transport utilities

* perf(tracing): add more log for streamable http session

* fix(test): fix port conflict in test with js

* fix(transport): fix id generating and session management

1. cancel when deleting
2. use `wrapping` and `saturating` correctly

* chore(naming): rename sse server to streamable http server

examples/servers/src/axum_streamable_http.rs

@@ -0,0 +1,29 @@
+use rmcp::transport::streamable_http_server::axum::StreamableHttpServer;
+use tracing_subscriber::{
+    layer::SubscriberExt,
+    util::SubscriberInitExt,
+    {self},
+};
+mod common;
+use common::counter::Counter;
+
+const BIND_ADDRESS: &str = "127.0.0.1:8000";
+
+#[tokio::main]
+async fn main() -> anyhow::Result<()> {
+    tracing_subscriber::registry()
+        .with(
+            tracing_subscriber::EnvFilter::try_from_default_env()
+                .unwrap_or_else(|_| "debug".to_string().into()),
+        )
+        .with(tracing_subscriber::fmt::layer())
+        .init();
+
+    let ct = StreamableHttpServer::serve(BIND_ADDRESS.parse()?)
+        .await?
+        .with_service(Counter::new);
+
+    tokio::signal::ctrl_c().await?;
+    ct.cancel();
+    Ok(())
+}