org-fold: Honour `org-fold-show-context-detail' for isearch

* lisp/org-fold.el (org-fold--isearch-reveal): Call
`org-fold-show-visibility'.  The previously used
`org-fold-show-set-visibility' does not accept context as argument.

Reported in https://orgmode.org/list/8735i5gd8n.fsf@gmail.com

lisp/org-fold.el

@@ -897,7 +897,7 @@ go to the parent and show the entire tree."
 
 (defun org-fold--isearch-reveal (&rest _)
   "Reveal text at POS found by isearch."
-  (org-fold-show-set-visibility 'isearch))
+  (org-fold-show-context 'isearch))
 
 ;;; Handling changes in folded elements