Fixed issue that will break the whole integration if TrueNAS is not connected to internet and added Czech translation

[Makhuta]

Proposed change

The "update/check_available" was able to result in error while not having access to the internet breaking the whole integration.

Type of change

• [x] Bugfix
• [x] New feature
• [ ] Code quality improvements to existing code or addition of tests
• [ ] Documentation

Additional information

This change will fix this issue by adding the ability to skip the error handling on query path if can_error_offline is set to True (default is False so the behaviour is as before for other things) and data returned will be None

Checklist

• [x] The code change is tested and works locally.
• [ ] The code has been formatted using Black.
• [ ] Tests have been added to verify that the new code works.
• [ ] Documentation added/updated if required.