Add Symfony Console command to allow running cron updates via console and by a separate user, for defense-in-depth

Not adding sprint tag right now as I figure out what else needs to be done for 📌 Enable unattended updates Fixed

core/scripts/db-tools.php might be a example of how to write a php file to invoke a console command.

\Drupal\Core\Command\ServerCommand::boot might be a example of how to create a command the boots

#3++

Why is this not ? Is this not blocking a commit to Drupal core? (Drupal core does not provide Drush commands, and we won't be allowed to change that.)

There is on todo left pointing to this issue in \Drupal\Tests\automatic_updates\Kernel\TestCronUpdateStage::runTerminalUpdateCommand()

// @todo Determine if the terminal command can be run in kernel tests when
    //   the Drush dependency is removed in https://drupal.org/i/3360485.
    //   Drush\TestTraits\DrushTestTrait only works with functional tests.

We don't actually need to run the command in kernel tests as of now so we could just remove the todo. We if we could run the command in kernel tests then we could probably convert StatusCheckFailureEmailTest back to kernel test which was before 📌 For web server dependent unattended updates run the entire life cycle in a separate process that will not be affected by hosting time limits Fixed but that is not super important as it does work as a functional.

Either way we need to remove the todo

Re #11, I have removed the todo. I don't think we can run the terminal command in kernel tests, because it needs to boot into a real(-ish) Drupal site with a real file system, and kernel tests don't have either of those things. (It's true that our kernel tests use the real file system for certain things, but those stub sites are not bootable.)

Looks good!

RTBC, hoping both branches pass

Automatically closed - issue fixed for 2 weeks with no activity.