Allow disabling issue tracker while retaining access to historic data
Release notes
Problem to solve
We have a range of related projects within a group, and have taken the decision that we want to have a single issue tracker, rather than per-project ones. Up to now we have used per-project issue trackers instead. While we can turn off the issue trackers in the projects we no longer want people to use, this means we lose access to history - what I would prefer to do is to be able to "lock" the issue tracker to prevent creation of new issues, but to allow existing issues to still be viewed, edited, closed etc.