Resolve #3443483 "Remember the position"

Closes #3443483

js/tree.js

@@ -66,6 +66,7 @@
   Drupal.TaxonomyManagerFancyTree = function (id, name, source) {
     // Settings generated by http://wwwendt.de/tech/fancytree/demo/sample-configurator.html
     $('#' + id).fancytree({
+      extensions: ["persist"],
       activeVisible: true, // Make sure, active nodes are visible (expanded).
       aria: false, // Enable WAI-ARIA support.
       autoActivate: true, // Automatically activate a node when it is focused (using keys).
@@ -119,6 +120,18 @@
       },
       focus: function (event, data) {
         new Drupal.TaxonomyManagerTermData(data.node.key, data.tree);
+      },
+      persist: {
+        expandLazy: true,
+        overrideSource: false,
+        store: 'session',
+      },
+      restore: function (event, data) {
+        // Check if the key exists in sessionStorage
+        if (sessionStorage.hasOwnProperty('fancytree-1-active')) {
+          // Open the active node.
+          new Drupal.TaxonomyManagerTermData(sessionStorage['fancytree-1-active'], data.tree);
+        }
       }
     });
   };