fix: move theme class to root node to prevent white flash (#392)

Alexander Sohn

18.46.2022 c36e1d8fff70ab6a817e00aa053b996342554681

 exampleSite/resources/_gen/assets/scss/scss/anatole.rtl.scss_97af51e696731e38130ed73ef4f4756e.json

@@ -1 +1 @@
{"Target":"scss/main.rtl.min.e137f9eb3f0f908b136886b05cefbccc97dd271959ef5d6748a7511abc3d8111.css","MediaType":"text/css","Data":{"Integrity":"sha256-4Tf56z8PkIsTaIawXO+8zJfdJxlZ711nSKdRGrw9gRE="}}
{"Target":"scss/main.rtl.min.a5eecfb30c244001796ebc324fb94c5c70ec99f77efddd26487bb075c44eb931.css","MediaType":"text/css","Data":{"Integrity":"sha256-pe7PswwkQAF5brwyT7lMXHDsmfd+/d0mSHuwdcROuTE="}}