Create radar archive from bundle

What does this MR do?

This merge request introduces minor changes for the bundle feature:

• In the template metadata file METADATA.yml.tpl, a rights_holder field is added, because this field is required by RADAR4KIT for publication. This field is autopopulated at the creation of bundles with the names of the authors.
• In the template metadata file METADATA.yml.tpl, the DOIs for openCARP and the openCARP paper were updated.

Author's checklist

• Follow the Contribution Guidelines.
• Apply the appropriate labels.
• Does this commit add new dependencies (e.g. Python modules)? If yes, please evaluate carefully if the additional dependency is a more sustainable option than including the functionality in own code. If the former, describe the dependency clearly, add them to the Software Management Plan and the installation instructions (*.md files, CMake files, Docker files etc.).

Reviewer's checklist

All reviewers can help ensure accuracy, clarity, completeness, and adherence to the Contribution Guidelines.

Reviewer

• Review by a code reviewer or other selected colleague to confirm accuracy, clarity, and completeness. This can be skipped for minor fixes without substantive content changes.

Maintainer

• Review by assigned maintainer, who can always request/require the above reviews.
• Ensure a release milestone is set.