Highlight focused element by path

Also force all its parents to be open, similar to forceOpen from the
previous commit (which, incidentally, this commit removes again).

gdn-app/src/stores/ui.ts

@@ -3,8 +3,10 @@ import { ref } from "vue";
 
 export const useUiStore = defineStore("ui", () => {
   const anchor = ref<string>();
+  const focusPath = ref<number[]>([1]);
 
   return {
     anchor,
+    focusPath,
   };
 });