Issue #3278418 by danflanagan8, quietone, nod_: Media Library Tests should not rely on Classy

.../tests/src/FunctionalJavascript/ContentModerationTest.php

...ts/src/FunctionalJavascript/EntityReferenceWidgetTest.php

...tests/src/FunctionalJavascript/FieldUiIntegrationTest.php

...y/tests/src/FunctionalJavascript/MediaLibraryTestBase.php

...rary/tests/src/FunctionalJavascript/MediaOverviewTest.php

...brary/tests/src/FunctionalJavascript/TranslationsTest.php

...tests/src/FunctionalJavascript/ViewsUiIntegrationTest.php

...brary/tests/src/FunctionalJavascript/WidgetAccessTest.php

...ry/tests/src/FunctionalJavascript/WidgetAnonymousTest.php

...brary/tests/src/FunctionalJavascript/WidgetOEmbedTest.php

...brary/tests/src/FunctionalJavascript/WidgetUploadTest.php

...ibrary/tests/src/FunctionalJavascript/WidgetViewsTest.php

...tests/src/FunctionalJavascript/WidgetWithoutTypesTest.php