Preserve original composer.json in the modules directory

Migrated issue

Reported by: moshe weitzman

Related to !72 (merged)

At https://drupal.slack.com/archives/CGKLP028K/p1698666859552099?thread_ts=1698666428.049529&cid=CGKLP028K, a request for a virgin composer.json in the modules/custom/[module-name] dir was made. There is no known problem with the current expanded composer.json, but there could be in the future.

To test this merge request, use these values for project and ref

 - project: issue/gitlab_templates-3397699
       ref: 3397699-preserve-original-composer-file

Also, because there is a change to scripts/symlink_project.php you need to set the following two variables:
_CURL_TEMPLATES_REPO: issue/gitlab_templates-3397699
_CURL_TEMPLATES_REF: 3397699-preserve-original-composer-file