Allow scheduled activation of CACs

The CAC editor should expose also the possibility to either maintain on/off times (which should then be considered by the https://github.com/wcm-io/wcm-io-caconfig/blob/develop/extensions/src/main/java/io/wcm/caconfig/extensions/persistence/impl/PagePersistenceStrategy.java). In addition it would be nice to be able to trigger a scheduled activation (similar to regular pages via "Manage Publication", compare with https://helpx.adobe.com/experience-manager/6-4/sites/authoring/using/publishing-pages.html#main-pars_title_cd34) via the CAC editor, in the best case for individual entries (WCON-69)