Creating an issue through "Add story to epic" that isn't on the board results in NPE

Click on add story to epic, then choose a project that is not on the board. You're greeted with an error when creating the issue.

The problem is that we try to reuse the issue loaded from the backlog in order to assign it to the epic. This does not work if the issue won't appear on the board!

Split the logic to separately fetch issue types after creating the issues and use that information to assign the issues to the epic. THEN reload the backlog.