Refactoring Issues Board ## What does this MR do? This MR aims to minimize conflicts between the CE issues board feature with EE multiple boards feature. ## Are there points in the code the reviewer needs to double check? ## Why was this MR needed? To avoid a lot of conflicts with EE multiple boards feature. ## Screenshots (if relevant) ## Does this MR meet the acceptance criteria? - [ ] ~~[CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added~~ - [ ] ~~[Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)~~ - [x] API support added - Tests - [X] Added for this feature/bug - [ ] All builds are passing - [x] Conform by the [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html) - [X] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides) - [ ] Branch has no merge conflicts with `master` (if you do - rebase it please) - [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits) ## What are the relevant issue numbers? https://gitlab.com/gitlab-org/gitlab-ee/issues/929 https://gitlab.com/gitlab-org/gitlab-ee/issues/1084 See merge request !6727
