[5.x] Add the scheduler system

[papac]

The scheduler should work like the following example:

$console->scheduler(function ($scheduler) {
    $scheduler->command("hello")->everyDay();
    $scheduler->php("hello")->everyDay();
});

You can use the externel package for implementing the scheduer. The command method must console the custom bowphp console command.

$console->addCommand('hello', function (Argument $argument) {
    echo Color::green("hello, bow task runner.");
});