feat: add shared API operation metadata macro

crates/api-macros/tests/ui/invalid_method_body.rs

@@ -0,0 +1,12 @@
+use api_macros::api;
+
+pub struct Request;
+pub struct Response;
+
+#[api]
+pub trait InvalidMethodBody {
+    #[get("/widgets")]
+    async fn list(&self, #[body] request: Request) -> Response;
+}
+
+fn main() {}