bug #6671 Align icon and text in a menu item (kniziol)

This PR was squashed before being merged into the 4.x branch.

Discussion
----------

Align icon and text in a menu item

# Menu configuration

It's not necessary. It's just added to have more menu items than a single, default menu item.

```php
// src/Controller/Admin/DashboardController.php:47

public function configureMenuItems(): iterable
{
    yield MenuItem::linkToDashboard('dashboard', 'fa fa-home');
    yield MenuItem::subMenu('Test', 'fas fa-list')
        ->setSubItems([
            MenuItem::linkToDashboard('dashboard', 'fa fa-home'),
            MenuItem::linkToDashboard('dashboard', 'fa fa-home'),
        ])
    ;
    // yield MenuItem::linkToCrud('The Label', 'fas fa-list', EntityClass::class);
}
```

# Before (the problem)

The icon in the menu item is currently aligned to the top. It would be so much more visually appealing if both the icon and text were centered together. Just take a look at the example below (in the `After` section).

![Icon and text alignment - before](https://github.com/user-attachments/assets/00472066-aff8-438f-9831-f0f9a8785874)

# After (the solution)

![Icon and text alignment - after](https://github.com/user-attachments/assets/8b1606e6-209f-430a-9ba7-65f2094fd4e8)

Commits
-------

3be8a66 Align icon and text in a menu item

assets/css/easyadmin-theme/menu.css

@@ -79,6 +79,7 @@
     text-align: center;
     block-size: 16px;
     inline-size: 1.25em;
+    margin-top: 3px;
 }
 #main-menu .menu .menu-icon svg {
     color: var(--sidebar-menu-icon-color);