Issue #2968110 by tedbow, tim.plunkett, Kristen Pol, bkosborne, andrewmacpherson: Layout Builder's ConfigureBlockFormBase forms do not display validation errors on submit

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