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/08-apis/scroll_to_offset.rs

@@ -0,0 +1,59 @@
+//! Scroll elements using their MountedData
+//!
+//! Dioxus exposes a few helpful APIs around elements (mimicking the DOM APIs) to allow you to interact with elements
+//! across the renderers. This includes scrolling, reading dimensions, and more.
+//!
+//! In this example we demonstrate how to scroll to a given y offset of the scrollable parent using the `scroll` method on the `MountedData`
+
+use dioxus::html::geometry::PixelsVector2D;
+use dioxus::prelude::*;
+
+fn main() {
+    dioxus::launch(app);
+}
+
+fn app() -> Element {
+    rsx! {
+        ScrollToCoordinates {}
+        ScrollToCoordinates {}
+    }
+}
+
+#[component]
+fn ScrollToCoordinates() -> Element {
+    let mut element = use_signal(|| None);
+
+    rsx! {
+        div { border: "1px solid black", position: "relative",
+
+            div {
+                height: "300px",
+                overflow_y: "auto",
+
+                onmounted: move |event| element.set(Some(event.data())),
+
+                for i in 0..100 {
+                    div { height: "20px", "Item {i}" }
+                }
+            }
+
+            div { position: "absolute", top: 0, right: 0,
+                input {
+                    r#type: "number",
+                    min: "0",
+                    max: "99",
+                    oninput: move |event| async move {
+                        if let Some(ul) = element.cloned() {
+                            let data = event.data();
+                            if let Ok(value) = data.parsed::<f64>() {
+                                ul.scroll(PixelsVector2D::new(0.0, 20.0 * value), ScrollBehavior::Smooth)
+                                    .await
+                                    .unwrap();
+                            }
+                        }
+                    },
+                }
+            }
+        }
+    }
+}