cherry-pick commits from twmr/secsgem?

[twmr]

Hi @bparzella!

Thx a lot for creating this python based secs-gem implementation. Do you know if your implementation already used in production?

In the last couple of months I've tried to improve the code in the main branch of my fork. Please have a look at my changes and feel free to cherry-pick some of them to your main branch. Let me know if you have questions about my changes.

https://github.com/bparzella/secsgem/compare/main...twmr:secsgem:main