FEATURE: add unlimited depth of subpages

app/Http/Controllers/Admin/CreateNewContent.php

@@ -56,7 +56,7 @@ class CreateNewContent extends Controller
             'templates'        => $templates,
             'moduleId'         => $moduleId,
             'page'             => $this->content,
-            'rootPages'        => $this->content->rootPages(),
+            'rootPages'        => $this->content->getOverview()->get(),
             'moduleName'       => trans($module->name),
             'extraData'        => call_user_func([$module->handler, 'loadExtraData'], $this->content),
             'formSectionNames' => call_user_func([$module->handler, 'getExtendedFormSections']),

app/Http/Controllers/Admin/EditContent.php

@@ -64,7 +64,9 @@ class EditContent extends Controller
         return view('admin.content.edit', [
             'contentStatuses'  => $statuses,
             'page'             => $page,
-            'rootPages'        => $page->rootPages(),
+            'rootPages'        => $page->getOverview()
+                                                ->where('contents.id', '!=', $page->id)
+                                                ->get(),
             'templates'        => $templates,
             'extraData'        => call_user_func([$page->module_handler, 'loadExtraData'], $page),
             'formSectionNames' => call_user_func([$page->module_handler, 'getExtendedFormSections']),