fix(management) Remove weird skipHeader toggle

This is specific to selectManagement and can be done by overridding getHeader

issue #6038

include/management/class_management.inc

@@ -81,9 +81,6 @@ class management
     ['ActionsColumn',    ['label' => 'Actions']],
   ];
 
-  // Whether to display a header or not.
-  protected $skipHeader = FALSE;
-
   function __construct (
     $objectTypes = FALSE,
     array $filterElementDefinitions = [
@@ -576,16 +573,12 @@ class management
   }
 
   /*!
-   * \brief  Generates the plugin header which is displayed whenever a tab object is opened.
+   * \brief Sets smarty headline and returns the plugin header which is displayed whenever a tab object is opened.
    */
   protected function getHeader (): string
   {
     global $smarty;
 
-    if ($this->skipHeader) {
-      return '';
-    }
-
     $smarty->assign('headline', $this->title);
     $smarty->assign('headline_image', $this->icon);
 

include/management/class_selectManagement.inc

@@ -24,7 +24,6 @@
  */
 class selectManagement extends management
 {
-  protected $skipHeader         = TRUE;
   protected $skipCpHandler      = TRUE;
   public static $skipSnapshots  = TRUE;
 
@@ -80,4 +79,12 @@ class selectManagement extends management
 
     return $list.$smarty->fetch(get_template_path('management/select-footer.tpl'));
   }
+
+  /*!
+   * \brief Let header handling to parent
+   */
+  protected function getHeader (): string
+  {
+    return '';
+  }
 }