The ignore_unavailable option should also ignore indices that are closed

PR for #6471
I see your point, on the other hand I think we can have options that are part of `IndicesOptions` although not exposed to users, even if they change only depending on the api. That was the direction in #6169. It would be great if we can keep a single `concreteIndices` method that knows what to do based on the `IndicesOptions` provided as argument and move this `canFailClosed` flag to `IndicesOptions` without exposing it to users.