Issue #2024963 by Berdir: Move baseFieldDefinitions from storage to entity classes.

...lib/Drupal/Core/Config/Entity/ConfigStorageController.php

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

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

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

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

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

...b/Drupal/Core/Entity/EntityStorageControllerInterface.php

.../modules/aggregator/lib/Drupal/aggregator/Entity/Feed.php

.../modules/aggregator/lib/Drupal/aggregator/Entity/Item.php

...ggregator/lib/Drupal/aggregator/FeedStorageController.php

...ggregator/lib/Drupal/aggregator/ItemStorageController.php

.../lib/Drupal/custom_block/CustomBlockStorageController.php

...stom_block/lib/Drupal/custom_block/Entity/CustomBlock.php

...s/comment/lib/Drupal/comment/CommentStorageController.php

core/modules/comment/lib/Drupal/comment/Entity/Comment.php

core/modules/contact/lib/Drupal/contact/Entity/Message.php

...s/contact/lib/Drupal/contact/MessageStorageController.php

core/modules/file/lib/Drupal/file/Entity/File.php

core/modules/file/lib/Drupal/file/FileStorageController.php

core/modules/node/lib/Drupal/node/Entity/Node.php