Issue #2995655 by awm, Sam152, jedgar1mx, lpeabody, axel.rutz: Invalid translation language (und) specified. in Drupal\Core\Entity\ContentEntityBase when changing language of an entity

Issue #2946402 by Sam152, awm, jibran, lamp5, mattshoaf, amateescu: Content moderation incorrectly always assumes a language is being added when the default language of an entity is being changed

Issue #808730 by awm, Anushka-mp, dpagini, Jo Fitzgerald, catch, johnv, venugopp, kim.pepper, kscheirer, miro_dietiker, Berdir, alexpott: Show the Revisions tab/page even when only one revision exists