Move rtic macros to repo root, tune xtask

rtic-macros/ui/local-not-declared.rs

@@ -0,0 +1,16 @@
+#![no_main]
+
+#[rtic_macros::mock_app(device = mock)]
+mod app {
+    #[shared]
+    struct Shared {}
+
+    #[local]
+    struct Local {}
+
+    #[task(local = [A])]
+    async fn foo(_: foo::Context) {}
+
+    #[init]
+    fn init(_: init::Context) -> (Shared, Local) {}
+}