Move axum-debug into axum-macros (#724)

* Move axum-debug into axum-macros

* fix ref to axum-macros in changelog

* Apply suggestions from code review

Co-authored-by: Jonas Platte <[email protected]>

Co-authored-by: Jonas Platte <[email protected]>

axum-macros/tests/debug_handler/fail/extract_self_ref.rs

@@ -0,0 +1,26 @@
+use axum::{
+    async_trait,
+    extract::{FromRequest, RequestParts},
+};
+use axum_macros::debug_handler;
+
+struct A;
+
+#[async_trait]
+impl<B> FromRequest<B> for A
+where
+    B: Send + 'static,
+{
+    type Rejection = ();
+
+    async fn from_request(_req: &mut RequestParts<B>) -> Result<Self, Self::Rejection> {
+        unimplemented!()
+    }
+}
+
+impl A {
+    #[debug_handler]
+    async fn handler(&self) {}
+}
+
+fn main() {}