Tests: add tests for hotreload and recurse into children

packages/rsx/tests/invalid/changedexpr.new.rsx

@@ -0,0 +1,9 @@
+use dioxus::prelude::*;
+
+pub fn CoolChild() -> Element {
+    rsx! {
+        div {
+            {some_expr()}
+        }
+    }
+}