Issue #3392572 by benjifisher, Liam Morland, ricovandevin, Anybody,...

Issue #3392572 by benjifisher, Liam Morland, ricovandevin, Anybody, smustgrave, quietone, sabrina.liman, carolpettirossi, longwave, alexpott: Add missing category to Drupal\layout_builder\Plugin\Layout\BlankLayout and let modules and themes alter the list of layouts

(cherry picked from commit cc32980f)