codify "platform" into resolution logic, server-fn/fullstack overhaul (#4596)

overhaul dioxus fullstack using a new implementation of server_fn

This PR is a complete rewrite of dioxus fullstack designed to improve compatibility with axum and to fix a number of compilation errors based on feature flag unification plumbing through macros.

examples/06-routing/router_resource.rs

@@ -0,0 +1,64 @@
+//! Example: Updating components with use_resource
+//! -----------------
+//!
+//! This example shows how to use ReadSignal to make props reactive
+//! when linking to it from the same component, when using use_resource
+
+use dioxus::prelude::*;
+
+#[derive(Clone, Routable, Debug, PartialEq)]
+enum Route {
+    #[route("/")]
+    Home {},
+    #[route("/blog/:id")]
+    Blog { id: i32 },
+}
+
+fn main() {
+    dioxus::launch(App);
+}
+
+#[component]
+fn App() -> Element {
+    rsx! {
+        Router::<Route> {}
+    }
+}
+
+// We use id: ReadSignal<i32> instead of id: i32 to make id work with reactive hooks
+// Any i32 we pass in will automatically be converted into a ReadSignal<i32>
+#[component]
+fn Blog(id: ReadSignal<i32>) -> Element {
+    async fn future(n: i32) -> i32 {
+        n
+    }
+
+    // Because we accept ReadSignal<i32> instead of i32, the resource will automatically subscribe to the id when we read it
+    let res = use_resource(move || future(id()));
+
+    match res() {
+        Some(id) => rsx! {
+            div {
+                "Blog post {id}"
+            }
+            for i in 0..10 {
+                div {
+                    Link { to: Route::Blog { id: i }, "Go to Blog {i}" }
+                }
+            }
+        },
+        None => rsx! {},
+    }
+}
+
+#[component]
+fn Home() -> Element {
+    rsx! {
+        Link {
+            to: Route::Blog {
+                id: 0
+            },
+            "Go to blog"
+        }
+    }
+}