Add class doc string to native_enum (#5617)

* add class doc string to native_enum

* adapt doc argument name

* fix test, make class enum doc None by default

* fix other python versions?

* make clang-tidy happy

* rename 'enum_doc' to 'class_doc'

* update documentation

* [skip ci] Polish changed documentation (mostly done by ChatGPT).

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Co-authored-by: Bryn Lloyd <12702862+dyollb@users.noreply.github.com>
Co-authored-by: Ralf W. Grosse-Kunstleve <rgrossekunst@nvidia.com>
5 files changed