Add direct link to gitlab repo from challenge title

[Berkanktk]

It would be super helpful if each challenge title on admin.haaukins.dk was clickable and opened its corresponding GitLab repository directly.

During events or maintenance, this would save a lot of time when jumping between the admin panel and the repo to check details, update content, or view solutions.

Proposed solution:

• Make each challenge title on the challenge list view a clickable link.
• The link should open the corresponding GitLab repository (ideally in a new tab).