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/simple_list.rs

@@ -0,0 +1,38 @@
+//! A few ways of mapping elements into rsx! syntax
+//!
+//! Rsx allows anything that's an iterator where the output type implements Into<Element>, so you can use any of the following:
+
+use dioxus::prelude::*;
+
+fn main() {
+    dioxus::launch(app);
+}
+
+fn app() -> Element {
+    rsx!(
+        div {
+            // Use Map directly to lazily pull elements
+            {(0..10).map(|f| rsx! { "{f}" })}
+
+            // Collect into an intermediate collection if necessary, and call into_iter
+            {["a", "b", "c", "d", "e", "f"]
+                .into_iter()
+                .map(|f| rsx! { "{f}" })
+                .collect::<Vec<_>>()
+                .into_iter()}
+
+            // Use optionals
+            {Some(rsx! { "Some" })}
+
+            // use a for loop where the body itself is RSX
+            for name in 0..10 {
+                div { "{name}" }
+            }
+
+            // Or even use an unterminated conditional
+            if true {
+                "hello world!"
+            }
+        }
+    )
+}