Issue #3379091 by phenaproxima, Wim Leers: Make NodeType config entities fully validatable

core/modules/book/config/optional/node.type.book.yml

...s/file_test_views/config/optional/node.type.file_test.yml

core/modules/forum/config/optional/node.type.forum.yml

...ntity_field_access_test/config/install/node.type.page.yml

...edia_library_test/config/install/node.type.basic_page.yml

...h_water_test/config/install/node.type.sql_import_node.yml

core/modules/node/config/schema/node.schema.yml

core/modules/node/node.post_update.php

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

core/modules/node/src/NodeTypeForm.php

...es/node/src/Plugin/migrate/destination/EntityNodeType.php

...s/update/remove-description-from-article-content-type.php

...les/node_test_config/config/install/node.type.default.yml

.../tests/modules/node_test_config/sync/node.type.import.yml

...ests/src/Functional/Update/NullHelpAndDescriptionTest.php

.../modules/node/tests/src/Kernel/NodeTypeValidationTest.php

...modules/olivero_test/config/install/node.type.article.yml

.../profiles/demo_umami/config/install/node.type.article.yml

core/profiles/demo_umami/config/install/node.type.page.yml

core/profiles/demo_umami/config/install/node.type.recipe.yml