Is your feature request related to a problem? Please describe.

The naming of the "iterator" classes & modules is misleading.

Describe the solution you'd like

Add a __next__ method so that a paged iterator can be used as an iterator.

Describe alternatives you've considered

Rename classes to "iterable" instead of iterator. This would be a breaking change, though.

Additional context

• Internal issue 186097906
• BigQuery: RowIterator is not an iterator, it is an Iterable google-cloud-python#9259