<details> <summary>Original description/proposal</summary> ### Description When we change the title of the issue, we create a system note for that. However this message has two problems: * the layout is weird (see below) * the visual importance is way too strong and draws the eyes too much  See https://gitlab.com/gitlab-org/gitlab-ce/issues/25872 for an exemple ### Proposal Enhance the system note about changing title so it takes way less visual space and doesn't draw the attention too much. Related to https://gitlab.com/gitlab-org/gitlab-ce/issues/19797 - Modified the layout. - Used the Bold font and darker text color, and lightened the background color to indicate the text has been changed. - If we get the system note icons back, there will be an Edit icon for editing title. <img src="/uploads/111308f23b2f11505c44eaeb806093a4/system-note--changing-title-v2.png" width=80% height=80%> cc @awhildy </details> ### Current implementation  ### Proposed design  * Username should be on the same line as the rest of the system message * Use `font-weight: 600` instead of `<strong>` for original title/new title * Text color of titles should be `#2e2e2e` -> `$gl-text-color`