Sync ReadSignal and Store (#4608)

* Add some traits read only signal works with sync storage

* seal gats

* minimize diff

packages/signals/examples/send_store.rs

@@ -0,0 +1,33 @@
+use dioxus::prelude::*;
+
+fn main() {
+    dioxus::launch(app);
+}
+
+fn app() -> Element {
+    let mut store = use_hook(|| Store::new_maybe_sync(0u32));
+
+    rsx! {
+        button { onclick: move |_| store += 1, "Increase" }
+        "{store}"
+        Child { store }
+    }
+}
+
+#[component]
+fn Child(store: WriteStore<u32, SyncStorage>) -> Element {
+    // A `WriteStore<T, SyncStorage>` can be sent to another thread!
+    // Make sure to clean up your threads when the component unmounts.
+    use_hook(|| {
+        std::thread::spawn(move || loop {
+            std::thread::sleep(std::time::Duration::from_secs(1));
+            store += 1;
+
+            if store() >= 10 {
+                break;
+            }
+        });
+    });
+
+    rsx! {}
+}