Add Leanlabs.io Kanban board service
What does this MR do?
This MR adds Leanlabs.io Kanban board service.
What Use Case does this MR solve?
In our company we use GitLab and Leanlabs.io Kanban board to manage issues. We have a policy to use kanban for several projects and GitLab issue tracker for others, and also we have use cases for support where there is no need in kanban board.
So we have use cases for both issue tracker and kanban board. So we added kanban service and link to it from project menu near the "Issues". Link visible only if service is active and user have access rights to view issues.