Issue #2421699 by JeroenT: Remove usage of deprecated functions of WebTestBase

core/modules/block/src/Tests/BlockRenderOrderTest.php

core/modules/comment/src/Tests/CommentBlockTest.php

core/modules/comment/src/Tests/CommentNonNodeTest.php

core/modules/comment/src/Tests/CommentTestBase.php

core/modules/config/src/Tests/ConfigExportImportUITest.php

core/modules/config/src/Tests/ConfigExportUITest.php

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

core/modules/datetime/src/Tests/DateTimeFieldTest.php

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

core/modules/field/src/Tests/Boolean/BooleanFieldTest.php

core/modules/field/src/Tests/Email/EmailFieldTest.php

core/modules/field/src/Tests/String/StringFieldTest.php

core/modules/field_ui/src/Tests/ManageDisplayTest.php

core/modules/file/src/Tests/FileListingTest.php

.../modules/history/src/Tests/Views/HistoryTimestampTest.php

core/modules/image/src/Tests/ImageThemeFunctionTest.php

core/modules/link/src/Tests/LinkFieldTest.php

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

.../modules/node/src/Tests/Views/NodeContextualLinksTest.php

...les/quickedit/src/Tests/QuickEditAutocompleteTermTest.php