Page - support for no sidebar #11759
Description
Follow up to core PR - patternfly/patternfly#7455
This adds .pf-m-no-sidebar to .pf-v6-c-page for layouts that do not have a sidebar. This takes a more explicit approach to the variations of the page layout, instead of us trying to detect the page markup and update the layout accordingly. This also solves bugs reported by a couple of products where they're using layouts with no masthead and/or sidebar, and does so as an opt-in, which gets us around the risk of introducing a change to the page component's base grid layout and potentially breaking folks layouts.
I chatted with @thatblindgeye and we tossed around the idea of adding this class via sidebar={null} as the opt-in. And in a future breaking change release, we could potentially update this to sidebar={false} (or just no sidebar prop, which is likely how folks are doing it now).