Macrobond-data-api

* Fix for DataPackageListPoller
* Fix for get_vintage_series
* Fix for Doc

* Fix for bug in get_data_package_list_iterative
* Add DataPackageListPoller

Adjusted name of Web API endpoint from getsubscriptionlist to getdatapackagelist

Renamed the original type of subscription list to _data package list_.

Added support for subscription lists
See example in https://github.com/macrobond/macrobond-data-api/blob/main/examples/subscribing_to_updates.py

- Better error messages when using automatic initialization
- Breaking change: get_series, get_many_series, get_entity, get_vintage_series and get_nth_release no longer uses *args for the set of series, but instead takes a sequence of series names
- Convenience methods get_one_vintage_series and get_one_nth_release have been added