View issue title real-time updates

Dependencies

• Verify that https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/9036 works in production, and we are satisfied with the performance. If that is the case, then we will start working on other parts of real-time, starting with this issue here.

Resources

PM @victorwu | FE @selfup | UX @dimitrieh

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Scope

• If the title changes in the system while you are viewing an issue page it should automatically be updated.
• This applies to both logged in and logged out users. Refer to https://gitlab.com/gitlab-org/gitlab-ce/issues/25051#note_25079195.
• The polling frequency should be determined in conjunction with the BE team here: https://gitlab.com/gitlab-org/gitlab-ce/issues/25051#note_25079195.

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Out of scope

• Other objects such as merge request titles are out of scope for this issue.
• This behavior only specifies what happens while viewing the issue page. Editing the issue and that behavior is out of scope.

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Design

• If there the title changes in the system, the title on the issue page you are viewing should cut out, and then should fade back in with 200ms linear, per the guidelines here: https://docs.gitlab.com/ce/development/ux_guide/animation.html#quick-update