Issue #3108109 by bnjmnm, lauriii: Decouple Classy libraries from Claro

...Drupal/KernelTests/Core/Theme/ConfirmClassyCopiesTest.php

...KernelTests/Core/Theme/ThemeNotUsingClassyLibraryTest.php

core/themes/claro/claro.info.yml

core/themes/claro/claro.libraries.yml

core/themes/claro/css/classy/components/book-navigation.css

core/themes/claro/css/classy/components/container-inline.css

core/themes/claro/css/classy/components/exposed-filters.css

core/themes/claro/css/classy/components/field.css

core/themes/claro/css/classy/components/file.css

core/themes/claro/css/classy/components/forum.css

core/themes/claro/css/classy/components/icons.css

core/themes/claro/css/classy/components/indented.css

core/themes/claro/css/classy/components/inline-form.css

core/themes/claro/css/classy/components/item-list.css

core/themes/claro/css/classy/components/link.css

core/themes/claro/css/classy/components/links.css

.../themes/claro/css/classy/components/media-embed-error.css

core/themes/claro/css/classy/components/menu.css

core/themes/claro/css/classy/components/more-link.css

core/themes/claro/css/classy/components/node.css