Delete items into the trash

Delete items by id, up to 50 per call. SOFT delete: every item stays recoverable for ~30 days via restore_deleted (type "item") before it is purged, and drops out of search. Returns the deleted items. An item inside a list shared with the user deletes as the app lets them, under its owner with the user named; ids the user may not delete — not theirs, or shared with them one item at a time — are reported under refused with the reason, and the rest still delete.