Add duplicate node counter functionality and tests (#508)

* Add node counter tests

* CI fixes

* Add comments

* Remove unnecessary test

* Add duplicate node functionality and tests

* Remove incrementation for DictOfNamedArrays and update tests

* Edit tests to account for not counting DictOfNamedArrays

* Fix CI tests

* Fix comments

* Clarify wording and clean up

* Move `get_node_multiplicities` to its own mapper

* Add autofunction

* Linting

* Add Dict typedef and format

* Format further

* Fix CI errors

* Fix wording

* Implement new DAG generator with guaranteed duplicates

* Apply suggestions from code review

Co-authored-by: Matt Smith <mjsmith1@gmail.com>

* Ruff fixes

* remove prints

* Apply suggestions from code review

Co-authored-by: Andreas Klöckner <inform@tiker.net>

* Add explicit bool for count_duplicates

* Update test/testlib.py

Co-authored-by: Andreas Klöckner <inform@tiker.net>

* Seed random

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Co-authored-by: Matt Smith <mjsmith1@gmail.com>
Co-authored-by: Andreas Klöckner <inform@tiker.net>
Co-authored-by: Matt Smith <mjsmith6@illinois.edu>