Preview visual changes for edits to dashboard settings

[eokoneyo]

Culled from #181450 (comment)

As of 8.14, a user is not able to conceive how changes to dashboard settings would be till until after applying these settings. It would better user experience to have changes to dashboard settings be previewed whilst the settings are being modified, this way the user is accepting exactly the change that was intended whilst modifying the settings for the dashboard.

A visual example of the proposed change can be seen below;

Screen.Recording.2024-05-03.at.15.50.01.mov

This should however extend beyond the useMargin setting and encompass other dashboard settings.

[elasticmachine]

Pinging @elastic/kibana-presentation (Team:Presentation)

[ThomThomson]

Closing this as we're adding it to our icebox for the time being.

Noting here also that this is a direction we'd like to head in, and if anyone is editing the Dashboard settings code and would like to do this, that would still be helpful with a few caveats:

1. It should be done for all dashboard settings
2. The settings flyout should become a push flyout
3. When the flyout is closed or canceled, the previous state is restored.