* Use background queue for database cache rebuild and track rebuilding status. * Updated OpenApi.json and client-side types. * Updated client to poll for completion of database rebuild. * Update src/Umbraco.Cms.Api.Management/Controllers/PublishedCache/RebuildPublishedCacheController.cs Co-authored-by: Sven Geusens <sge@umbraco.dk> * Removed unnecessary obsolete attribute. --------- Co-authored-by: Sven Geusens <sge@umbraco.dk>