Issue #3117217 by bnjmnm, lauriii: Decouple core theme dependency on functions in stable.theme

core/modules/filter/src/Element/TextFormat.php

...ofiles/demo_umami/themes/umami/css/theme/filter.admin.css

...format/container--text-format-filter-guidelines.html.twig

.../text_format/container--text-format-filter-help.html.twig

...xt_format/container--text-format-filter-wrapper.html.twig

core/profiles/demo_umami/themes/umami/umami.info.yml

core/profiles/demo_umami/themes/umami/umami.libraries.yml

core/profiles/demo_umami/themes/umami/umami.theme

core/themes/bartik/bartik.info.yml

core/themes/bartik/bartik.libraries.yml

core/themes/bartik/bartik.theme

core/themes/bartik/css/theme/filter.admin.css

...format/container--text-format-filter-guidelines.html.twig

.../text_format/container--text-format-filter-help.html.twig

...xt_format/container--text-format-filter-wrapper.html.twig

core/themes/claro/claro.info.yml

core/themes/claro/claro.libraries.yml

...format/container--text-format-filter-guidelines.html.twig

.../text_format/container--text-format-filter-help.html.twig

...xt_format/container--text-format-filter-wrapper.html.twig