Issue #2674408 by alexpott, dawehner: Fix Drupal.Classes.UnusedUseStatement standard in core

core/includes/common.inc

core/lib/Drupal/Core/DrupalKernel.php

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

...ore/EventSubscriber/CustomPageExceptionHtmlSubscriber.php

core/lib/Drupal/Core/Field/BaseFieldDefinition.php

core/lib/Drupal/Core/Render/Element/Fieldset.php

core/lib/Drupal/Core/Render/Element/Form.php

core/lib/Drupal/Core/Render/Element/Pager.php

core/lib/Drupal/Core/Render/Element/Textarea.php

core/lib/Drupal/Core/Routing/MatcherDumper.php

core/lib/Drupal/Core/TypedData/TypedDataInterface.php

core/modules/comment/src/CommentViewBuilder.php

...odules/comment/src/Plugin/Field/FieldType/CommentItem.php

.../comment/src/Plugin/migrate/destination/EntityComment.php

...omment/src/Tests/CommentDefaultFormatterCacheTagsTest.php

...nfig/src/Tests/CacheabilityMetadataConfigOverrideTest.php

core/modules/content_translation/content_translation.module

...ation/src/Tests/ContentTranslationContextualLinksTest.php

..._cache/src/EventSubscriber/DynamicPageCacheSubscriber.php

core/modules/editor/src/Tests/EditorLoadingTest.php