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/10-integrations/pwa/index.html

@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <title>{app_title}</title>
+    <script>
+      if ("serviceWorker" in navigator) {
+        navigator.serviceWorker.register("/{base_path}/assets/sw.js");
+      }
+    </script>
+    <link rel="manifest" href="/assets/manifest.json" />
+    <meta content="text/html;charset=utf-8" http-equiv="Content-Type" />
+    <meta name="viewport" content="width=device-width, initial-scale=1" />
+    <meta charset="UTF-8" />
+  </head>
+  <body>
+    <div id="main"></div>
+  </body>
+</html>