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/cli/src/main.rs

@@ -18,6 +18,7 @@ mod rustcwrapper;
 mod serve;
 mod settings;
 mod tailwind;
+mod test_harnesses;
 mod wasm_bindgen;
 mod wasm_opt;
 mod workspace;