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.

packages/web/src/cfg.rs

@@ -14,6 +14,7 @@ use wasm_bindgen::JsCast as _;
 /// ```
 pub struct Config {
     pub(crate) hydrate: bool,
+    #[allow(dead_code)]
     pub(crate) panic_hook: bool,
     pub(crate) root: ConfigRoot,
     #[cfg(feature = "document")]