Confidential MRs don't look confidential
Continuation from conversation in https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/29984#note_189656257
Problem to solve
Confidential MRs don't look confidential, there is no icon or identifier to show that it's confidential.
Creating a confidential MR from https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/29984 makes it feel like it's not confidential, which could confuse people in thinking the MR they created isn't in fact confidential. Showing a confidential identifier would fix this confusion, ensuring that the MR they created is in fact confidential.
Show confidential option in the right sidebar, similar to confidential issues:
What does success look like, and how can we measure that?
When someone creates a confidential MR, they can verify visually that the MR created is confidential.