Automatic merge from submit-queue (batch tested with PRs 41134, 41410, 40177, 41049, 41313)
apiserver: further cleanup of apiserver storage plumbing
- move kubeapiserver`s `RESTOptionsFactory` back to EtcdOptions by adding a `AddWithStorageFactoryTo`
- factor out storage backend `Config` construction from EtcdOptions
- move all `StorageFactory` related code into server/storage subpackage.
In short: remove my stomach ache about `kubeapiserver.RESTOptionsFactory`.
approved based on #40363