[11.x] Fix schedule:list to handle fluent-style scheduling constraints

[Gajarthan]

Fix schedule:list to handle fluent-style scheduling constraints

Issue: php artisan schedule:list does not correctly display tasks that use fluent-style scheduling methods such as between().

Example:

$schedule->command('emails:send')
         ->hourly()
         ->between('7:00', '22:00');

[taylorotwell]

No tests or doc blocks.