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/cli/src/build/patch.rs

@@ -1191,6 +1191,8 @@ pub fn prepare_wasm_base_module(bytes: &[u8]) -> Result<Vec<u8>> {
         })
         .collect::<HashMap<_, _>>();
 
+    let mut exported = HashSet::new();
+
     // Wasm-bindgen will synthesize imports to satisfy its external calls. This facilitates things
     // like inline-js, snippets, and literally the `#[wasm_bindgen]` macro. All calls to JS are
     // just `extern "wbg"` blocks!
@@ -1227,9 +1229,10 @@ pub fn prepare_wasm_base_module(bytes: &[u8]) -> Result<Vec<u8>> {
 
             let new_func_id = module.funcs.add_local(builder.local_func(locals));
 
-            module
-                .exports
-                .add(&format!("__saved_wbg_{}", import.name), new_func_id);
+            let saved_name = format!("__saved_wbg_{}", import.name);
+            if exported.insert(saved_name.clone()) {
+                module.exports.add(&saved_name, new_func_id);
+            }
 
             make_indirect.push(new_func_id);
         }
@@ -1254,9 +1257,10 @@ pub fn prepare_wasm_base_module(bytes: &[u8]) -> Result<Vec<u8>> {
         //
         // https://github.com/rustwasm/wasm-bindgen/blob/c35cc9369d5e0dc418986f7811a0dd702fb33ef9/crates/cli-support/src/wit/mod.rs#L1505
         if name.starts_with("__wbindgen") {
-            module
-                .exports
-                .add(&format!("__saved_wbg_{name}"), func.id());
+            let saved_name = format!("__saved_wbg_{}", name);
+            if exported.insert(saved_name.clone()) {
+                module.exports.add(&saved_name, func.id());
+            }
         }
 
         // This is basically `--export-all` but designed to work around wasm-bindgen not properly gc-ing