Option and Tap watches never send the initial-events-end bookmark #4465

The Option and Tap resources in core.cozystack.io never end the initial events of a WatchList watch. Their Watch sends the current list as ADDED events and then blocks, without the bookmark annotated with k8s.io/initial-events-end. A client that opens the watch with sendInitialEvents=true and allowWatchBookmarks=true, which is what a client-go informer does with WatchListClient on, keeps waiting for that bookmark and never reaches HasSynced from the stream.

The other aggregated storages handle this through registry.InitialEventsBookmarker and registry.InitialEventsEndBookmarkRequested. The one-shot watchers are in option/rest.go and tap/rest.go.

Emitting the marker after the last ADDED event, only when both flags are set, should be enough. A watch test with both flags that expects ADDED events and then the annotated bookmark would pin it.