Allow MenuSection to be an external link

[dmason30]

In Nova 3 I used tools to display items on the menu with icons these were external links to their relevant dashboards.

In Nova 4 we can easily add tools using the menu() method on our Tool classes however, to replicate the above behaviour of displaying it as an a external link at the moment the only Menu class that supports external links is MenuItem but you cannot

App\Nova\Tools\InboxTool.php

public function menu() {
    return MenuItem::externalLink('Horizon', route('horizon'))
}

Displays in the menu like this

Proposed
Allow MenuSection to be an externalLink:

public function menu() {
    return MenuSection::externalLink('Horizon', route('horizon'))
         ->icon('sun')
}

Which would display like this and open in a new tab when clicked

Workaround
This works in displaying correctly but instead of opening a new tab it opens the url in an overlay over the portal which is cool but would much prefer opening in a new tab!

public function menu(Request $request)
{
    return MenuSection::make('Horizon')
        ->path(URL::remote(route('horizon')))
        ->icon('sun');
}