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/01-app-demos/ecommerce-site/src/api.rs

@@ -0,0 +1,106 @@
+use chrono::{DateTime, Utc};
+use dioxus::prelude::Result;
+use serde::{Deserialize, Serialize};
+use std::fmt::Display;
+
+// Cache up to 100 requests, invalidating them after 60 seconds
+pub(crate) async fn fetch_product(product_id: usize) -> Result<Product> {
+    Ok(
+        reqwest::get(format!("https://fakestoreapi.com/products/{product_id}"))
+            .await?
+            .json()
+            .await?,
+    )
+}
+
+// Cache up to 100 requests, invalidating them after 60 seconds
+pub(crate) async fn fetch_products(count: usize, sort: Sort) -> Result<Vec<Product>> {
+    Ok(reqwest::get(format!(
+        "https://fakestoreapi.com/products/?sort={sort}&limit={count}"
+    ))
+    .await?
+    .json()
+    .await?)
+}
+
+#[derive(Serialize, Deserialize, PartialEq, Clone, Debug, Default)]
+pub(crate) struct Product {
+    pub(crate) id: u32,
+    pub(crate) title: String,
+    pub(crate) price: f32,
+    pub(crate) description: String,
+    pub(crate) category: String,
+    pub(crate) image: String,
+    pub(crate) rating: Rating,
+}
+
+#[derive(Serialize, Deserialize, PartialEq, Clone, Debug, Default)]
+pub(crate) struct Rating {
+    pub(crate) rate: f32,
+    pub(crate) count: u32,
+}
+
+impl Display for Rating {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let rounded = self.rate.round() as usize;
+        for _ in 0..rounded {
+            "★".fmt(f)?;
+        }
+        for _ in 0..(5 - rounded) {
+            "☆".fmt(f)?;
+        }
+
+        write!(f, " ({:01}) ({} ratings)", self.rate, self.count)?;
+
+        Ok(())
+    }
+}
+
+#[allow(unused)]
+#[derive(Clone, Copy, Hash, PartialEq, Eq, PartialOrd)]
+pub(crate) enum Sort {
+    Descending,
+    Ascending,
+}
+
+impl Display for Sort {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Sort::Descending => write!(f, "desc"),
+            Sort::Ascending => write!(f, "asc"),
+        }
+    }
+}
+
+#[derive(Serialize, Deserialize)]
+struct User {
+    id: usize,
+    email: String,
+    username: String,
+    password: String,
+    name: FullName,
+    phone: String,
+}
+
+#[derive(Serialize, Deserialize)]
+struct FullName {
+    firstname: String,
+    lastname: String,
+}
+
+#[derive(Serialize, Deserialize, Clone)]
+struct Cart {
+    id: usize,
+    #[serde(rename = "userId")]
+    user_id: usize,
+    data: String,
+    products: Vec<ProductInCart>,
+    date: DateTime<Utc>,
+}
+
+#[derive(Serialize, Deserialize, Clone)]
+struct ProductInCart {
+    #[serde(rename = "productId")]
+    product_id: usize,
+    quantity: usize,
+}