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/spread.rs

@@ -0,0 +1,43 @@
+//! This example demonstrates how to use the spread operator to pass attributes to child components.
+//!
+//! This lets components like the `Link` allow the user to extend the attributes of the underlying `a` tag.
+//! These attributes are bundled into a `Vec<Attribute>` which can be spread into the child component using the `..` operator.
+
+use dioxus::prelude::*;
+
+fn main() {
+    let dom = VirtualDom::prebuilt(app);
+    let html = dioxus_ssr::render(&dom);
+
+    println!("{}", html);
+}
+
+fn app() -> Element {
+    rsx! {
+        SpreadableComponent {
+            width: "10px",
+            extra_data: "hello{1}",
+            extra_data2: "hello{2}",
+            height: "10px",
+            left: 1,
+            "data-custom-attribute": "value",
+        }
+    }
+}
+
+#[derive(Props, PartialEq, Clone)]
+struct Props {
+    #[props(extends = GlobalAttributes)]
+    attributes: Vec<Attribute>,
+
+    extra_data: String,
+
+    extra_data2: String,
+}
+
+#[component]
+fn SpreadableComponent(props: Props) -> Element {
+    rsx! {
+        audio { ..props.attributes, "1: {props.extra_data}\n2: {props.extra_data2}" }
+    }
+}