Ensure only translation keys are added to client side translations for menu entries

[sgiehl]

Description:

Matomo provides the possibility for plugins to create the own menu entries. An example code would be

<?php
/**
 * Piwik - free/libre analytics platform
 *
 * @link https://matomo.org
 * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
 */

namespace Piwik\Plugins\PluginName;

use Piwik\Menu\MenuAdmin;
use Piwik\Piwik;

class Menu extends \Piwik\Plugin\Menu
{

    public function configureAdminMenu(MenuAdmin $menu)
    {
        if (Piwik::hasUserSuperUserAccess()) {
            $menu->addItem('Menu name', "Do some magic", $this->urlForAction('performAction'));
        }
    }
}

The menu entries can be provided as translation keys of strings. Currently Matomo has a problem when strings are provided for the top level, as it always tries to add them to the client side translations. There it fails to translate them.

fixes #22853

Review

• Functional review done
• Potential edge cases thought about (behavior of the code with strange input, with strange internal state or possible interactions with other Matomo subsystems)
• Usability review done (is anything maybe unclear or think about anything that would cause people to reach out to support)
• Security review done
• Wording review done
• Code review done
• Tests were added if useful/possible
• Reviewed for breaking changes
• Developer changelog updated if needed
• Documentation added if needed
• Existing documentation updated if needed