Implement top navigation for profile area
Main idea is to keep left sidebar static so user is not confused by
changing context. Instead we put changing navigation with changing
content in one main block. I used profile area as a simplest way to
implement and test this concept. Your feedback is welcome in comments
For https://gitlab.com/gitlab-org/gitlab-ce/issues/14354#note_4878536
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
See merge request !3824
f4859b93a5