Issue #2930534 by ddavidd, if-jds, sdewitt, rickmanelius, andrewmacpherson, benjifisher, jerseycheese: Seven pager items do not meet WCAG AA 1.4.3 for contrast

Issue #2936511 by hchonov, Berdir, plach, Wim Leers, catch, amateescu, sdewitt: ContentEntityType::getRevisionMetadataKeys() never considers the BC logic because of the new "revision_default" key

Issue #2930542 by sahil432, sdewitt, andrewmacpherson: Disabled form labels in Seven theme's node meta-data  do not meet WCAG AA 1.4.3 Contrast (minimum)