bpo-42327: Add PyModule_Add().

[serhiy-storchaka]

https://bugs.python.org/issue42327

[bedevere-bot]

🤖 New build scheduled with the buildbot fleet by @pablogsal for commit 17279ae 🤖

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[tiran]

Could you please move your changes of _ssl.c to another PR? This PR will cause major conflicts with two of my PRs.

I also like to get your opinion on https://discuss.python.org/t/define-module-constants-in-pymoduledef/5749 . I have suggested a radically different approach for module constant initialization that is even more convenient than PyModule_Add().

[bedevere-bot]

When you're done making the requested changes, leave the comment: I have made the requested changes; please review again.

[serhiy-storchaka]

I will most likely break this PR into several parts and merge them separately. It grew more than I expected because for each modified module I fixed all potential leaks, and some module expose many constants.

[serhiy-storchaka]

Created #23443 which does not include large changes.

[github-actions]

This PR is stale because it has been open for 30 days with no activity.

[serhiy-storchaka]

Split and merged as a number of smaller PRs.