more fullstack cleanups: loaders serialize, ServeConfig only (#4785)

* some opinionated cleanups in dioxus-server

* add serialize to loader

* add `result` to Resource

* clippy

* fix

* writable memos, resources, `onmount`, `.pending`, and `.value()` on actions

* fix compile issues

* fix typo

examples/07-fullstack/ssr-only/src/main.rs

@@ -36,12 +36,12 @@ fn Home() -> Element {
 }
 
 #[component]
-fn Post(id: u32) -> Element {
+fn Post(id: ReadSignal<u32>) -> Element {
     // You can return `HttpError` to return a specific HTTP status code and message.
     // `404 Not Found` will cause the server to return a 404 status code.
     //
     // `use_loader` will suspend the server-side rendering until the future resolves.
-    let post_data = use_loader(move || get_post(id))?;
+    let post_data = use_loader(move || get_post(id()))?;
 
     rsx! {
         h1 { "Post {id}" }