[8.x] Create ScheduleTestCommand

[browner12]

Currently, we have a couple ways to run scheduled jobs in our local environments. In Homestead we can enable schedule:run to be enabled for a site. We also have the relatively new schedule:work command that starts a long running worker in your terminal.

I've never turned on scheduling in Homestead, because I don't want the jobs running running around the clock on there. And while schedule:work is nice, chances are you are going to need to manipulate when your commands are scheduled if you want to run some of them. You're not going to wait around for a command that runs at 1AM every morning.

As a (hopefully) simpler alternative, this PR introduces a new command that allows you to execute whichever scheduled task you'd like.

php artisan schedule:test

Then make your selection, and the scheduled command will run.

While we are no longer testing the timing aspect of the scheduled job, we are still able to see the side effects from things like sendOutputTo(), hooks, and pings, and we are able to test truth and environment constraints.

[taylorotwell]

You need to actually register the command with the framework.

[browner12]

Ahh yes, made the same mistake as the guy who created schedule:work. Forgot things weren't auto-registered in core.

Updated now.

[kcaj-burr]

Using invokable objects in the schedule and running the command will display a list of keys only. The keys are not selectable, except pressing return will invoke the first class.

Altering line 36 as below will show the class names of the invokable objects which would be acceptable.

$commandNames[] = $command->command ?? $command->description;

I have not tested this on a clean install.