✨ Added critical temperature domain simulation

[Drewniok]

Description

This PR addresses issue #20 by adding the critical temperature domain simulation. It can be chosen via a checkbox if the "normal" operational domain or the critical temperature one is wanted.

Checklist:

• The pull request only contains commits that are related to it.
• I have added appropriate tests and documentation.
• I have added a changelog entry.
• I have created/adjusted the Python bindings for any new or updated functionality.
• I have made sure that all CI jobs on GitHub pass.
• The pull request introduces no new warnings and follows the project's style guidelines.

[Drewniok]

The clicked parameter point is shown when clicking on the operational domain plot. Should we add the critical temperature as a third entry when clicking on a point in the critical temperature plot, @marcelwa. I think it needs, however, some refactoring.

[marcelwa]

Thank you so much for the addition! 🙏 The entire code base needs some refactoring I fear 😅 Going through it currently just makes me awfully aware of how quickly it was put together 😬

[Drewniok]

@Drewniok, @marcelwa Add critical temperature domain to README.