When opening a change stream on a timeseries view, it should be rewritten into a change stream on the underlying buckets collection.

We should update DocumentSourceChangeStream::getNsRegexForChangeStream to also match the underlying buckets collection if featureFlagTimeSeriesChangeStreams is enabled. There is no need to extend the regex for existing non-timeseries collections.

We may also need to check the system.buckets collections for some DDL information. ChangeStreamEventTransformer::getBuilder can check system.buckets the way it already checks system.views. Alternatively, we could create a custom transformer, which would apply the default ChangeStreamEventTransformer and then transform that output.