XWIKI-8596: Retire the Toucan Skin

xwiki-platform-core/pom.xml

xwiki-platform-core/xwiki-platform-toucan/pom.xml

...platform-core/xwiki-platform-toucan/src/assemble/skin.xml

...-platform-toucan/src/main/resources/toucan/contentmenu.vm

...orm-toucan/src/main/resources/toucan/css/colors/black.css

...form-toucan/src/main/resources/toucan/css/colors/blue.css

...-toucan/src/main/resources/toucan/css/colors/darkblue.css

...-toucan/src/main/resources/toucan/css/colors/darkgray.css

...form-toucan/src/main/resources/toucan/css/colors/gray.css

...orm-toucan/src/main/resources/toucan/css/colors/green.css

...form-toucan/src/main/resources/toucan/css/colors/kaki.css

...rm-toucan/src/main/resources/toucan/css/colors/orange.css

...rm-toucan/src/main/resources/toucan/css/colors/purple.css

...tform-toucan/src/main/resources/toucan/css/colors/red.css

...tform-toucan/src/main/resources/toucan/docdoesnotexist.vm

...iki-platform-toucan/src/main/resources/toucan/docextra.vm

...e/xwiki-platform-toucan/src/main/resources/toucan/edit.vm

...i-platform-toucan/src/main/resources/toucan/editinline.vm

...iki-platform-toucan/src/main/resources/toucan/editmeta.vm

...ki-platform-toucan/src/main/resources/toucan/editmodes.vm