Issue #2935779 by tim.plunkett, EclipseGc, webchick, xjm, dead_arm: Come up with an affordance for what parts of the page are/are not affected by Layout Builder

Issue #2921626 by tim.plunkett, EclipseGc, larowlan, dead_arm, xjm: Add proper context-awareness to Layout Builder

Revert "Issue #2921626 by tim.plunkett, EclipseGc, larowlan, dead_arm: Add proper context-awareness to Layout Builder"

This reverts commit 749f41ff.

Issue #2921626 by tim.plunkett, EclipseGc, larowlan, dead_arm: Add proper context-awareness to Layout Builder

Issue #2928450 by tim.plunkett: Remove dead code in the Layout Builder following Section refactoring

Issue #2905922 by tim.plunkett, tedbow, xjm, EclipseGc, webchick, vijaycs85, larowlan, andrewmacpherson, droplet, Bojhan, mgifford, drpal, phenaproxima, DyanneNova, japerry: Implementation issue for Layout Builder

Revert "Issue #2905922 by tim.plunkett, xjm, EclipseGc, vijaycs85, webchick, larowlan, andrewmacpherson, Bojhan, droplet, mgifford, drpal, japerry, tedbow, DyanneNova, phenaproxima: Implementation issue for Layout Builder"

This reverts commit 88a22dda.

Issue #2905922 by tim.plunkett, xjm, EclipseGc, vijaycs85, webchick, larowlan, andrewmacpherson, Bojhan, droplet, mgifford, drpal, japerry, tedbow, DyanneNova, phenaproxima: Implementation issue for Layout Builder