NEPT-1668: Allow to define commands in runner.yml.dist

[ademarco]

Currently setup is scattered in several locations, we should harmonize that making sure that users can set it up in their runner.yml.dist, something like:

commands:

  setup:dev:
    - { task: "symlink", from: "${drupal.root}/modules/custom", to: "custom/modules" }
    - { task: "symlink", from: "${drupal.root}/modules/custom", to: "custom/themes" }
    - { task: "symlink", from: "${drupal.root}/modules/profiles", to: "custom/profiles" }
    - { task: "process", source: "behat.yml.dist", destination: "behat.yml.dist" }
    - { task: "process", source: "phpunit.xml.dist", destination: "phpunit.xml.dist" }

  setup:dist:
    - { task: "mirror", origin: "custom/modules",  target: "${drupal.root}/modules/custom" }
    - { task: "mirror", origin: "custom/themes",   target: "${drupal.root}/modules/custom" }
    - { task: "mirror", origin: "custom/profiles", target: "${drupal.root}/modules/profiles" }

That will expose:

$ ./vendor/bin/run setup:dev
$ ./vendor/bin/run setup:dist

Also this will allow to have setup:* commands being exposed in runner.yml.