[PP-1] Try to work out a way to update the preview on undo without a POST

Overview

After 📌 Replace the postPreview action with atomic equivalents Active the only remaining place where we POST the whole layout model is on UNDO/REDO to update the preview.
In theory we should be able to treat undo/redo as a reverse of the action it performed and then only POST that change for compatibility with mulit-user environments

Proposed resolution

Explore that approach

User interface changes