[5.3] allow passing object instance to class_uses_recursive

[jarektkaczyk]

This PR makes class_uses_recursive more useful and compatible with class_uses native function:

As you can see in the screenshot, when you try to feed it with an object, rather than class name, you get pretty annoying and useless error message.

This PR gets rid of that:

>>> class_uses_recursive('App\User')
=> [
     "Illuminate\Notifications\Notifiable" => "Illuminate\Notifications\Notifiable",
     "Illuminate\Notifications\HasDatabaseNotifications" => "Illuminate\Notifications\HasDatabaseNotifications",
     "Illuminate\Notifications\RoutesNotifications" => "Illuminate\Notifications\RoutesNotifications",
     "Illuminate\Auth\Authenticatable" => "Illuminate\Auth\Authenticatable",
     "Illuminate\Foundation\Auth\Access\Authorizable" => "Illuminate\Foundation\Auth\Access\Authorizable",
     "Illuminate\Auth\Passwords\CanResetPassword" => "Illuminate\Auth\Passwords\CanResetPassword",
   ]
>>> class_uses_recursive(new App\User)
=> [
     "Illuminate\Notifications\Notifiable" => "Illuminate\Notifications\Notifiable",
     "Illuminate\Notifications\HasDatabaseNotifications" => "Illuminate\Notifications\HasDatabaseNotifications",
     "Illuminate\Notifications\RoutesNotifications" => "Illuminate\Notifications\RoutesNotifications",
     "Illuminate\Auth\Authenticatable" => "Illuminate\Auth\Authenticatable",
     "Illuminate\Foundation\Auth\Access\Authorizable" => "Illuminate\Foundation\Auth\Access\Authorizable",
     "Illuminate\Auth\Passwords\CanResetPassword" => "Illuminate\Auth\Passwords\CanResetPassword",
   ]
>>>