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/hydration/hydrate.rs

@@ -8,7 +8,7 @@ use dioxus_core::{
     AttributeValue, DynamicNode, ElementId, ScopeId, ScopeState, SuspenseBoundaryProps,
     SuspenseContext, TemplateNode, VNode, VirtualDom,
 };
-use dioxus_fullstack_protocol::HydrationContext;
+use dioxus_fullstack_core::HydrationContext;
 use futures_channel::mpsc::UnboundedReceiver;
 use std::fmt::Write;
 use RehydrationError::*;