fix: Avoid rerendering assets when new messages arrive

[atomrc]

Description

When a new message comes in, the last sent message visibleCallback get updated. But we could actually have this callback stable over time and avoid extra re-renderings.

Screenshots/Screencast (for UI changes)

Before

Screen.Recording.2024-02-05.at.11.37.14.mov

After

Screen.Recording.2024-02-05.at.11.38.36.mov

Checklist

• PR has been self reviewed by the author;
• Hard-to-understand areas of the code have been commented;
• If it is a core feature, unit tests have been added;