Better error messages for Ambiguous end DoesntExistInZone exceptions (#26)

[exoriente]

For issue #26

Description

Better error messages for the Ambiguous and Doesn't Exist errors. Examples:

• 2023-10-29 02:15:00 is ambiguous in the system timezone
• 2023-10-29 02:15:00 is ambiguous in timezone Europe/Amsterdam
• 2023-03-26 02:15:00 doesn't exist in the system timezone
• 2023-03-26 02:15:00 doesn't exist in timezone Europe/Amsterdam

Instead of checking the behavior of the methods added to the exceptions I'm checking the message in every place the error is checked in any test. It's a bit more work but this way we can be sure the errors are always generated correctly.

Checklist

I did all the check on my local system, but have not performed any of the other steps as they seem more of a maintainer's responsibility. Let me know if you expect more.

• [x] tox runs successfully
• [x] Docs updated
• [ ] Version updated in pyproject.toml
• [ ] Version updated in changelog
• [ ] Branch merged
• [ ] Tag created and pushed
• [ ] Published
• [ ] Github release created

[ariebovenberg]

I did all the check on my local system, but have not performed any of the other steps as they seem more of a maintainer's responsibility. Let me know if you expect more.

Indeed. I'll make an adjustment in the PR template

[ariebovenberg]

@exoriente also, I just remembered: there are some examples of the exceptions being raised in docs/overview.rst. They also need to be updated with the better messages.

[exoriente]

@ariebovenberg All done! ✅

[ariebovenberg]

🚀 thanks for your contribution 🤝