Provide default monolog configuration

Out of the box, the Ironstar module should configure Monolog (if it’s installed) with default options for writing log files.

These should match what we usually do for best practices.

Ordinarily we’d get Drupal logs going to /app/logs/drupal.log by adding the following to web/sites/default/monolog.services.yml

parameters:
  monolog.channel_handlers:
    default: ['stream']
  monolog.processors: ['message_placeholder', 'current_user', 'request_uri', 'ip', 'referer', 'filter_backtrace', 'memory_usage']

services:
  monolog.handler.stream:
    class: Monolog\Handler\StreamHandler
    arguments: ['/app/logs/drupal.log', 'NOTICE', 'monolog.level.notice']

And then adding this line to web/sites/default/settings.php:

$settings['container_yamls'][] = $app_root . '/' . $site_path . '/monolog.services.yml';

If possible, the Ironstar module should automatically create this configuration so customers don’t need to add extra steps other than just simply installing and enabling the Monolog module.

This log file should be enabled by default, but customers should be able to turn it off via a config flag.