View issues in the Web IDE

When I'm working on adding, fixing or reviewing a code change, I want to be able to reference the issue while I'm working in the Web IDE, so that I can make sure I implement the right changes in the right way based on what has been documented and discussed in the issue, without having to keep the issue open in a separate tab and switch to it.

We should make it possible to view an issue including its description and comments in the Web IDE, so that I can spend more time in the web ide, and less time switching between GitLab tabs.

Proposal

Add ability to open an issue in the right panel.

We'll need a way of finding or switching to other issues too.

Links

• https://blog.janestreet.com/putting-the-i-back-in-ide-towards-a-github-explorer/
• https://gitlab.com/gitlab-org/gitlab-ce/issues/45176