Merge branch 'feature/ISTWCMS-4678-kpaxman-automatically_add_new_menu_items' into '8.x-1.x'

ISTWCMS-4678: treat never-configured additions as enabled until selected otherwise

See merge request !8

src/Plugin/Block/ContentManagementMenuBlock.php

@@ -58,7 +58,10 @@ class ContentManagementMenuBlock extends BlockBase implements ContainerFactoryPl
             // default.
             if (isset($configured[$id])) {
               foreach ($secondary_menu as $key => $value) {
-                if (!empty($configured[$id][$key])) {
+                // Show the menu if they've configured it to be shown, or if
+                // it's never been configured either way, so that new items
+                // appear automatically.
+                if (!isset($configured[$id][$key]) || !empty($configured[$id][$key])) {
                   $selected_secondary[] = $key;
                 }
               }