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/hooks/Cargo.toml

@@ -19,7 +19,7 @@ dioxus-signals = { workspace = true }
 futures-channel = { workspace = true }
 tracing = { workspace = true }
 slab = { workspace = true }
-futures-util = { workspace = true}
+futures-util = { workspace = true, features = ["std"] }
 generational-box = { workspace = true }
 rustversion = { workspace = true }
 warnings = { workspace = true }