Issue #2506213 by hchonov, mkalkbrenner: Update content entity changed timestamp on UI save

core/lib/Drupal/Core/Entity/ContentEntityForm.php

core/lib/Drupal/Core/Entity/EntityChangedInterface.php

core/lib/Drupal/Core/Entity/EntityChangedTrait.php

...alidation/Constraint/EntityChangedConstraintValidator.php

core/modules/block_content/src/Entity/BlockContent.php

core/modules/comment/src/Entity/Comment.php

...les/content_translation/src/ContentTranslationHandler.php

...nt_translation/src/Tests/ContentTranslationUITestBase.php

core/modules/file/src/Entity/File.php

.../modules/menu_link_content/src/Entity/MenuLinkContent.php

core/modules/node/src/Entity/Node.php

core/modules/node/src/Tests/NodeFormSaveChangedTimeTest.php

core/modules/rest/src/Tests/RESTTestBase.php

.../modules/entity_test/src/Entity/EntityTestConstraints.php

...s/modules/entity_test/src/Entity/EntityTestMulChanged.php

core/modules/taxonomy/src/Entity/Term.php

core/modules/user/src/Entity/User.php