Add Wizard::isComplete()

Wizard::isFinished() is not applicable in case a wizard is a child of another
wizard. Wizard::isComplete() fulfills the need to check whether a user went
through a wizard entirely.

refs #8191

library/Icinga/Web/Wizard.php

@@ -487,6 +487,19 @@ class Wizard
         return $page->getName() === end($pages)->getName();
     }
 
+    /**
+     * Return whether all of this wizard's pages were visited by the user
+     *
+     * The base implementation just verifies that the very last page has page data available.
+     *
+     * @return  bool
+     */
+    public function isComplete()
+    {
+        $pages = $this->getPages();
+        return $this->hasPageData($pages[count($pages) - 1]->getName());
+    }
+
     /**
      * Set whether this wizard has been completed
      *