NXP-15452: Add a way of restoring a ContentView from a ContentView state.
NXP-15198: remove nuxeo-platform-ui-api module + remove non-ajaxified widgets types handling selection, relying on seam remoting + cleanup default layouts/widgets, handling compatibility with old layouts/widgets handling selection
NXP-15522: add a content view action to trigger the slideshow
NXP-15522: cleanup