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/09-reference/shorthand.rs

@@ -0,0 +1,44 @@
+//! Dioxus supports shorthand syntax for creating elements and components.
+
+use dioxus::prelude::*;
+
+fn main() {
+    dioxus::launch(app);
+}
+
+fn app() -> Element {
+    let a = 123;
+    let b = 456;
+    let c = 789;
+    let class = "class";
+    let id = "id";
+
+    // todo: i'd like it for children on elements to be inferred as the children of the element
+    // also should shorthands understand references/dereferences?
+    // ie **a, *a, &a, &mut a, etc
+    let children = rsx! { "Child" };
+    let onclick = move |_| println!("Clicked!");
+
+    rsx! {
+        div { class, id, {&children} }
+        Component { a, b, c, children, onclick }
+        Component { a, ..ComponentProps { a: 1, b: 2, c: 3, children: VNode::empty(), onclick: Default::default() } }
+    }
+}
+
+#[component]
+fn Component(
+    a: i32,
+    b: i32,
+    c: i32,
+    children: Element,
+    onclick: EventHandler<MouseEvent>,
+) -> Element {
+    rsx! {
+        div { "{a}" }
+        div { "{b}" }
+        div { "{c}" }
+        div { {children} }
+        div { onclick }
+    }
+}